document_title: All-time Olympic Games medal table

question_text: who has the most medals in the olympic games

text: All-time Olympic Games medal table

text: NOCs with medals[edit]

text: The table is pre-sorted by the name of each Olympic Committee, but can be displayed as sorted by any other column, such as the total number of gold medals or total number of overall medals. To sort by gold, silver, and then bronze, sort first by the bronze column, then the silver, and then the gold. The table does not include revoked medals (e.g. due to doping).

text: Medal totals in this table are current as of the 2018 Winter Olympics in Pyeongchang County, South Korea, and all changes in medal standings due to doping cases up to and including 25 February 2018 are taken into account.

text:
Summer Games
Winter Games
Combined Total

Team (IOC code)

№

01 !

02 !

03 !

Total

№

01 !

02 !

03 !

Total

№

01 !

02 !

03 !

Total

 Afghanistan (AFG)
14
0
0
2
2
0
0
0
0
0
14
0
0
2
2

 Algeria (ALG)
13
5
4
8
17
3
0
0
0
0
16
5
4
8
17

 Argentina (ARG)
24
21
25
28
74
19
0
0
0
0
43
21
25
28
74

 Armenia (ARM)
6
2
6
6
14
7
0
0
0
0
13
2
6
6
14

 Australasia (ANZ) [ANZ]
2
3
4
5
12
0
0
0
0
0
2
3
4
5
12

 Australia (AUS) [AUS] [Z]
26
147
163
187
497
19
5
5
5
15
45
152
168
192
512

 Austria (AUT)
27
18
33
36
87
23
64
81
87
232
50
82
114
123
319

 Azerbaijan (AZE)
6
7
11
25
43
6
0
0
0
0
12
7
11
25
43

 Bahamas (BAH)
16
6
2
6
14
0
0
0
0
0
16
6
2
6
14

 Bahrain (BRN)
9
2
1
0
3
0
0
0
0
0
9
2
1
0
3

 Barbados (BAR) [BAR]
12
0
0
1
1
0
0
0
0
0
12
0
0
1
1

 Belarus (BLR)
6
12
27
39
78
7
8
5
5
18
13
20
32
44
96

 Belgium (BEL)
26
40
53
55
148
21
1
2
3
6
47
41
55
58
154

 Bermuda (BER)
18
0
0
1
1
8
0
0
0
0
26
0
0
1
1

 Bohemia (BOH) [BOH] [Z]
3
0
1
3
4
0
0
0
0
0
3
0
1
3
4

 Botswana (BOT)
10
0
1
0
1
0
0
0
0
0
10
0
1
0
1

 Brazil (BRA)
22
30
36
62
128
8
0
0
0
0
30
30
36
62
128

 British West Indies (BWI) [BWI]
1
0
0
2
2
0
0
0
0
0
1
0
0
2
2

 Bulgaria (BUL) [H]
20
51
87
80
218
20
1
2
3
6
40
52
89
83
224

 Burundi (BDI)
6
1
1
0
2
0
0
0
0
0
6
1
1
0
2

 Cameroon (CMR)
14
3
1
2
6
1
0
0
0
0
15
3
1
2
6

 Canada (CAN)
26
64
102
136
302
23
73
64
62
199
49
137
166
198
501

 Chile (CHI) [I]
23
2
7
4
13
17
0
0
0
0
40
2
7
4
13

 China (CHN) [CHN]
10
224
167
155
546
11
13
28
21
62
21
237
195
176
608

 Colombia (COL)
19
5
9
14
28
2
0
0
0
0
21
5
9
14
28

 Costa Rica (CRC)
15
1
1
2
4
6
0
0
0
0
21
1
1
2
4

 Ivory Coast (CIV) [CIV]
13
1
1
1
3
0
0
0
0
0
13
1
1
1
3

 Croatia (CRO)
7
11
10
12
33
8
4
6
1
11
15
15
16
13
44

 Cuba (CUB) [Z]
20
78
68
79
225
0
0
0
0
0
20
78
68
79
225

 Cyprus (CYP)
10
0
1
0
1
11
0
0
0
0
21
0
1
0
1

 Czech Republic (CZE) [CZE]
6
15
17
24
56
7
9
11
11
31
13
24
28
35
87

 Czechoslovakia (TCH) [TCH]
16
49
49
45
143
16
2
8
15
25
32
51
57
60
168

 Denmark (DEN) [Z]
27
45
74
75
194
14
0
1
0
1
41
45
75
75
195

 Djibouti (DJI) [B]
8
0
0
1
1
0
0
0
0
0
8
0
0
1
1

 Dominican Republic (DOM)
14
3
2
2
7
0
0
0
0
0
14
3
2
2
7

 Ecuador (ECU)
14
1
1
0
2
1
0
0
0
0
15
1
1
0
2

 Egypt (EGY) [EGY] [Z]
22
7
10
15
32
1
0
0
0
0
23
7
10
15
32

 Eritrea (ERI)
5
0
0
1
1
1
0
0
0
0
6
0
0
1
1

 Estonia (EST)
12
9
9
16
34
10
4
2
1
7
22
13
11
17
41

 Ethiopia (ETH)
13
22
11
20
53
2
0
0
0
0
15
22
11
20
53

 Fiji (FIJ)
14
1
0
0
1
3
0
0
0
0
17
1
0
0
1

 Finland (FIN)
25
101
85
117
303
23
43
63
61
167
48
144
148
178
470

 France (FRA) [O] [P] [Z]
28
212
241
263
716
23
36
35
53
124
51
248
276
316
840

 Gabon (GAB)
10
0
1
0
1
0
0
0
0
0
10
0
1
0
1

 Georgia (GEO)
6
8
8
17
33
7
0
0
0
0
13
8
8
17
33

 Germany (GER) [GER] [Z]
16
191
194
230
615
12
92
88
60
240
28
283
282
290
855

 United Team of Germany (EUA) [EUA]
3
28
54
36
118
3
8
6
5
19
6
36
60
41
137

 East Germany (GDR) [GDR]
5
153
129
127
409
6
39
36
35
110
11
192
165
162
519

 West Germany (FRG) [FRG]
5
56
67
81
204
6
11
15
13
39
11
67
82
94
243

 Ghana (GHA) [GHA]
14
0
1
3
4
2
0
0
0
0
16
0
1
3
4

 Great Britain (GBR) [GBR] [Z]
28
263
295
291
849
23
11
4
16
31
51
274
299
307
880

 Greece (GRE) [Z]
28
33
43
40
116
19
0
0
0
0
47
33
43
40
116

 Grenada (GRN)
9
1
1
0
2
0
0
0
0
0
9
1
1
0
2

 Guatemala (GUA)
14
0
1
0
1
1
0
0
0
0
15
0
1
0
1

 Guyana (GUY) [GUY]
17
0
0
1
1
0
0
0
0
0
17
0
0
1
1

 Haiti (HAI) [J]
15
0
1
1
2
0
0
0
0
0
15
0
1
1
2

 Hong Kong (HKG) [HKG]
16
1
1
1
3
5
0
0
0
0
21
1
1
1
3

 Hungary (HUN)
26
175
147
169
491
23
1
2
4
7
49
176
149
173
498

 Iceland (ISL)
20
0
2
2
4
18
0
0
0
0
38
0
2
2
4

 India (IND) [F]
24
9
7
12
28
10
0
0
0
0
34
9
7
12
28

 Indonesia (INA)
15
7
13
12
32
0
0
0
0
0
15
7
13
12
32

 Iran (IRI) [K]
16
19
22
28
69
11
0
0
0
0
27
19
22
28
69

 Iraq (IRQ)
14
0
0
1
1
0
0
0
0
0
14
0
0
1
1

 Ireland (IRL)
21
9
10
12
31
7
0
0
0
0
28
9
10
12
31

 Israel (ISR)
16
1
1
7
9
7
0
0
0
0
23
1
1
7
9

 Italy (ITA) [M] [S]
27
206
178
193
577
23
40
36
48
124
50
246
214
241
701

 Jamaica (JAM) [JAM]
17
22
35
20
77
8
0
0
0
0
25
22
35
20
77

 Japan (JPN)
22
142
135
162
439
21
14
22
22
58
43
156
157
184
497

 Jordan (JOR)
10
1
0
0
1
0
0
0
0
0
10
1
0
0
1

 Kazakhstan (KAZ)
6
15
20
27
62
7
1
3
4
8
13
16
23
31
70

 Kenya (KEN)
14
31
38
33
102
4
0
0
0
0
18
31
38
33
102

 Kosovo (KOS)
1
1
0
0
1
1
0
0
0
0
2
1
0
0
1

 North Korea (PRK)
10
16
16
22
54
9
0
1
1
2
19
16
17
23
56

 South Korea (KOR)
17
90
87
90
267
18
31
25
14
70
35
121
112
104
337

 Kuwait (KUW)
12
0
0
2
2
0
0
0
0
0
12
0
0
2
2

 Kyrgyzstan (KGZ)
6
0
1
3
4
7
0
0
0
0
13
0
1
3
4

 Latvia (LAT)
11
3
11
5
19
11
0
4
4
8
22
3
15
9
27

 Lebanon (LIB)
17
0
2
2
4
17
0
0
0
0
34
0
2
2
4

 Liechtenstein (LIE)
17
0
0
0
0
19
2
2
6
10
36
2
2
6
10

 Lithuania (LTU)
9
6
7
12
25
9
0
0
0
0
18
6
7
12
25

 Luxembourg (LUX) [O]
23
1
1
0
2
9
0
2
0
2
32
1
3
0
4

 Macedonia (MKD)
6
0
0
1
1
6
0
0
0
0
12
0
0
1
1

 Malaysia (MAS) [MAS]
13
0
7
4
11
1
0
0
0
0
14
0
7
4
11

 Mauritius (MRI)
9
0
0
1
1
0
0
0
0
0
9
0
0
1
1

 Mexico (MEX)
23
13
24
32
69
9
0
0
0
0
32
13
24
32
69

 Moldova (MDA)
6
0
2
3
5
7
0
0
0
0
13
0
2
3
5

 Mongolia (MGL)
13
2
10
14
26
14
0
0
0
0
27
2
10
14
26

 Montenegro (MNE)
3
0
1
0
1
3
0
0
0
0
6
0
1
0
1

 Morocco (MAR)
14
6
5
12
23
7
0
0
0
0
21
6
5
12
23

 Mozambique (MOZ)
10
1
0
1
2
0
0
0
0
0
10
1
0
1
2

 Namibia (NAM)
7
0
4
0
4
0
0
0
0
0
7
0
4
0
4

 Netherlands (NED) [Z]
26
85
92
108
285
21
45
44
41
130
47
130
136
149
415

 Netherlands Antilles (AHO) [AHO] [I]
13
0
1
0
1
2
0
0
0
0
15
0
1
0
1

 New Zealand (NZL) [NZL]
23
46
27
44
117
16
0
1
2
3
39
46
28
46
120

 Niger (NIG)
12
0
1
1
2
0
0
0
0
0
12
0
1
1
2

 Nigeria (NGR)
16
3
10
12
25
1
0
0
0
0
17
3
10
12
25

 Norway (NOR) [Q]
25
56
49
47
152
23
132
125
111
368
48
188
174
158
520

 Pakistan (PAK)
17
3
3
4
10
3
0
0
0
0
20
3
3
4
10

 Panama (PAN)
17
1
0
2
3
0
0
0
0
0
17
1
0
2
3

 Paraguay (PAR)
12
0
1
0
1
1
0
0
0
0
13
0
1
0
1

 Peru (PER) [L]
18
1
3
0
4
2
0
0
0
0
20
1
3
0
4

 Philippines (PHI)
21
0
3
7
10
5
0
0
0
0
26
0
3
7
10

 Poland (POL)
21
68
83
133
284
23
7
7
8
22
44
75
90
141
306

 Portugal (POR)
24
4
8
12
24
8
0
0
0
0
32
4
8
12
24

 Puerto Rico (PUR)
18
1
2
6
9
7
0
0
0
0
25
1
2
6
9

 Qatar (QAT)
9
0
1
4
5
0
0
0
0
0
9
0
1
4
5

 Romania (ROU)
21
89
95
122
306
21
0
0
1
1
42
89
95
123
307

 Russia (RUS) [RUS]
6
149
124
153
426
6
47
38
35
120
12
196
162
188
546

 Russian Empire (RU1) [RU1]
3
1
4
3
8
0
0
0
0
0
3
1
4
3
8

 Soviet Union (URS) [URS]
9
395
319
296
1,010
9
78
57
59
194
18
473
376
355
1,204

 Saudi Arabia (KSA)
11
0
1
2
3
0
0
0
0
0
11
0
1
2
3

 Samoa (SAM)
9
0
1
0
1
0
0
0
0
0
9
0
1
0
1

 Senegal (SEN)
14
0
1
0
1
5
0
0
0
0
19
0
1
0
1

 Serbia (SRB) [SRB]
4
3
6
6
15
3
0
0
0
0
7
3
6
6
15

 Serbia and Montenegro (SCG) [SCG]
1
0
2
0
2
1
0
0
0
0
2
0
2
0
2

 Singapore (SIN)
16
1
2
2
5
1
0
0
0
0
17
1
2
2
5

 Slovakia (SVK) [SVK]
6
9
12
7
28
7
3
4
1
8
13
12
16
8
36

 Slovenia (SLO)
7
5
8
10
23
8
2
5
10
17
15
7
13
20
40

 South Africa (RSA)
19
26
31
29
86
7
0
0
0
0
26
26
31
29
86

 Spain (ESP) [Z]
23
45
64
41
150
20
1
0
3
4
43
46
64
44
154

 Sri Lanka (SRI) [SRI]
17
0
2
0
2
0
0
0
0
0
17
0
2
0
2

 Sudan (SUD)
12
0
1
0
1
0
0
0
0
0
12
0
1
0
1

 Suriname (SUR) [E]
12
1
0
1
2
0
0
0
0
0
12
1
0
1
2

 Sweden (SWE) [Z]
27
145
170
179
494
23
57
46
55
158
50
202
216
234
652

 Switzerland (SUI)
28
50
75
67
192
23
55
46
52
153
51
105
121
119
345

 Syria (SYR)
13
1
1
1
3
0
0
0
0
0
13
1
1
1
3

 Chinese Taipei (TPE) [TPE] [TPE2]
14
5
7
12
24
12
0
0
0
0
26
5
7
12
24

 Tajikistan (TJK)
6
1
1
2
4
4
0
0
0
0
10
1
1
2
4

 Tanzania (TAN) [TAN]
13
0
2
0
2
0
0
0
0
0
13
0
2
0
2

 Thailand (THA)
16
9
8
16
33
4
0
0
0
0
20
9
8
16
33

 Togo (TOG)
10
0
0
1
1
2
0
0
0
0
12
0
0
1
1

 Tonga (TGA)
9
0
1
0
1
2
0
0
0
0
11
0
1
0
1

 Trinidad and Tobago (TRI) [TRI]
17
2
6
11
19
3
0
0
0
0
20
2
6
11
19

 Tunisia (TUN)
14
4
2
7
13
0
0
0
0
0
14
4
2
7
13

 Turkey (TUR)
22
39
24
28
91
17
0
0
0
0
39
39
24
28
91

 Uganda (UGA)
15
2
3
2
7
0
0
0
0
0
15
2
3
2
7

 Ukraine (UKR)
6
35
30
56
121
7
3
1
4
8
13
38
31
60
129

 United Arab Emirates (UAE)
9
1
0
1
2
0
0
0
0
0
9
1
0
1
2

 United States (USA) [P] [Q] [R] [Z]
27
1,022
795
705
2,522
23
105
110
90
305
50
1,127
905
795
2,827

 Uruguay (URU)
21
2
2
6
10
1
0
0
0
0
22
2
2
6
10

 Uzbekistan (UZB)
6
8
6
17
31
7
1
0
0
1
13
9
6
17
32

 Venezuela (VEN)
18
2
3
10
15
4
0
0
0
0
22
2
3
10
15

 Vietnam (VIE)
15
1
3
0
4
0
0
0
0
0
15
1
3
0
4

 Virgin Islands (ISV)
12
0
1
0
1
7
0
0
0
0
19
0
1
0
1

 Yugoslavia (YUG) [YUG]
18
28
31
31
90
16
0
3
1
4
34
28
34
32
94

 Zambia (ZAM) [ZAM]
13
0
1
1
2
0
0
0
0
0
13
0
1
1
2

 Zimbabwe (ZIM) [ZIM]
13
3
4
1
8
1
0
0
0
0
14
3
4
1
8

 Unified Team (EUN) [EUN]
1
45
38
29
112
1
9
6
8
23
2
54
44
37
135

 Independent Olympic Athletes (IOA) [IOA]
3
1
0
1
2
0
0
0
0
0
3
1
0
1
2

 Independent Olympic Participants (IOP) [IOP]
1
0
1
2
3
0
0
0
0
0
1
0
1
2
3

 Olympic Athletes from Russia (OAR) [OAR]
0
0
0
0
0
1
2
6
9
17
1
2
6
9
17

 Mixed team (ZZX) [ZZX]
3
8
5
4
17
0
0
0
0
0
3
8
5
4
17

Totals
28
5,115
5,080
5,482
15,677
23
1,060
1,058
1,050
3,168
51
6,175
6,138
6,532
18,845

text: The sum total of gold, silver and bronze medals are not equal for the following reasons:

text:
Some sports (such as boxing, judo, taekwondo and wrestling) award or have previously awarded two bronze medals per competition.
Some tied performances have resulted in multiple medals of the same colour being awarded for an event. If this tie is for gold or silver, there will be a consequent absence of a silver or bronze medal for that event.
Not all medals which have been revoked have been re-awarded.
Some early events, such as cricket at the 1900 Summer Olympics had only two entrants.
Retroactively awarding gold, silver and bronze medals for the 1896 and 1900 games results in some anomalies, such as the 100 metre freestyle swimming event in 1896 where no surviving records distinguish the places of those who finished between 3rd and 10th position.

tag: ul

text: NOCs without medals[edit]

text: After the 2018 Winter Olympics in Pyeongchang, 71 of the current 206 National Olympic Committees have yet to win an Olympic medal. Seven historic National Olympic Committees and the Refugee Olympic Team are also included in this list.

text:
Team (IOC code)
№ Summer
№ Winter
№ Games

 Albania (ALB)
8
4
12

 American Samoa (ASA)
8
1
9

 Andorra (AND)
11
12
23

 Angola (ANG)
9
0
9

 Antigua and Barbuda (ANT)
10
0
10

 Aruba (ARU)
8
0
8

 Bangladesh (BAN)
9
0
9

 Belize (BIZ) [BIZ]
12
0
12

 Benin (BEN) [BEN]
11
0
11

 Bhutan (BHU)
9
0
9

 Bolivia (BOL)
14
6
20

 Bosnia and Herzegovina (BIH)
7
7
14

 British Virgin Islands (IVB)
9
2
11

 Brunei (BRU) [A]
5
0
5

 Burkina Faso (BUR) [BUR]
9
0
9

 Cambodia (CAM)
9
0
9

 Cape Verde (CPV)
6
0
6

 Cayman Islands (CAY)
10
2
12

 Central African Republic (CAF)
10
0
10

 Chad (CHA)
12
0
12

 Comoros (COM)
6
0
6

 Congo (CGO)
12
0
12

 Democratic Republic of the Congo (COD) [COD]
10
0
10

 Cook Islands (COK)
8
0
8

 Dominica (DMA)
6
1
7

 El Salvador (ESA)
11
0
11

 Equatorial Guinea (GEQ)
9
0
9

 The Gambia (GAM)
9
0
9

 Guam (GUM)
8
1
9

 Guinea (GUI)
11
0
11

 Guinea-Bissau (GBS)
6
0
6

 Honduras (HON)
11
1
12

 Kiribati (KIR)
4
0
4

 Korea (COR)
0
1
1

 Laos (LAO)
9
0
9

 Lesotho (LES)
11
0
11

 Liberia (LBR) [C]
12
0
12

 Libya (LBA) [D]
10
0
10

 Madagascar (MAD)
12
2
14

 Malawi (MAW)
10
0
10

 Maldives (MDV)
8
0
8

 Mali (MLI)
13
0
13

 Malta (MLT)
16
2
18

 Marshall Islands (MHL)
3
0
3

 Mauritania (MTN)
9
0
9

 Federated States of Micronesia (FSM)
5
0
5

 Monaco (MON) [N]
20
10
30

 Myanmar (MYA) [MYA]
17
0
17

 Nauru (NRU)
6
0
6

 Nepal (NEP)[a]
13
4
17

 Nicaragua (NCA)
12
0
12

 Oman (OMA)
9
0
9

 Palau (PLW)
5
0
5

 Palestine (PLE)
6
0
6

 Papua New Guinea (PNG)
10
0
10

 Rwanda (RWA)
9
0
9

 Saint Kitts and Nevis (SKN)
6
0
6

 Saint Lucia (LCA)
6
0
6

 Saint Vincent and the Grenadines (VIN)
8
0
8

 San Marino (SMR)
14
10
24

 São Tomé and Príncipe (STP)
6
0
6

 Seychelles (SEY)
9
0
9

 Sierra Leone (SLE)
11
0
11

 Solomon Islands (SOL)
9
0
9

 Somalia (SOM)
9
0
9

 South Sudan (SSD)
1
0
1

 Swaziland (SWZ)
10
1
11

 East Timor (TLS) [I]
4
2
6

 Turkmenistan (TKM)
6
0
6

 Tuvalu (TUV)
3
0
3

 Vanuatu (VAN)
8
0
8

 Yemen (YEM) [YEM]
7
0
7

 North Borneo (NBO) [NBO]
1
0
1

 Malaya (MAL) [MAL]
2
0
2

 Republic of China (ROC) [ROC]
3
0
3

 Saar (SAA) [SAA]
1
0
1

 North Yemen (YAR) [YAR]
2
0
2

 South Yemen (YMD) [YMD]
1
0
1

 Refugee Olympic Team (ROT) [ROT]
1
0
1

text: ^ Tejbir Bura was the first and only Nepalese person to receive an Olympic gold medal. During the 1924 Winter Olympic closing ceremony, the IOC awarded a gold medal in alpinism for the 1922 British Mount Everest expedition, which recognized 21 mountaineers, including the first athletes to be awarded medals posthumously, seven Indian sherpas who were killed in an avalanche on the third and last attempt to summit.[2]

tag: ol

text: Variations[edit]

text: The sections above are based on information published by the International Olympic Committee. Various sources deal with some of the entries in the preceding sections differently.

text: Early Olympics[edit]

text: For the 1900 Summer Olympics several countries are credited with appearances that are not considered official by the IOC. Only one of these cases concerns a medal. A gold medal that is officially added to France's total is given to Luxembourg.[3]

text: Similar cases of disputed nationality affect the 1904 Summer Olympics. France is credited with a silver medal[4] and Norway with two gold medals.[5] In the table above these medals are listed under the United States. Furthermore, Newfoundland is occasionally listed as a separate country at the 1904 Olympics, and would be listed as a historical NOC without medals.[6]

text: Other differences from the official table are based on disagreements about which events were Olympic. This affects several of the events in the 1900 and 1904 Olympics. In addition, some sources include the 1906 Intercalated Games when compiling their medal tables.[7]

text: Alpinism and aeronautics[edit]

text: From 1924 through 1936, the IOC on several occasions awarded gold medals for feats of alpinism and aeronautics that occurred in the preceding four-year Olympiad. In 1924, 1932 and 1936, gold medals were awarded to 25 mountaineers from six nations for expeditions in the Himalayas and the Matterhorn. In 1936, a gold medal was awarded to Hermann Schreiber of Switzerland for crossing the Alps in a glider in 1935, the first time that had been done.[2][8][9][10] Some sources include these IOC awards of gold medals in the overall count.

text: Germany[edit]

text: Germany has competed under five different designations, including as two separate teams at several Games. Sources vary in how they present the medals won by these teams. The table below shows sourced combinations of these teams, when applied to the updated medal totals from the main table.

text:
Summer Games
Winter Games
Combined Total

Team (IOC code)

№

01 !

02 !

03 !

Total

№

01 !

02 !

03 !

Total

№

01 !

02 !

03 !

Total

 Germany (GER)[11]
16
191
192
232
615
12
92
88
60
240
28
283
280
292
855

 Germany (GER) (EUA)[12]
19
219
246
268
733
15
100
94
65
259
34
319
340
333
992

 Germany (GER) (EUA) (FRG)[13]
24
275
313
349
937
21
111
109
78
298
45
386
422
427
1235

 Germany (GER) (EUA) (FRG) (GDR)[14]
25[15]
428
442
476
1346
21
150
145
113
408
46[15]
578
587
589
1754

text: Russia and the Soviet Union[edit]

text: The Russian Federation, the Russian Empire and the Olympic Athletes from Russia are often combined outside of IOC sources. The Soviet Union is sometimes combined with the post-union team that competed in 1992. Few sources combine the Soviet Union and Russia as many republics which subsequently gained independence (Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Tadjikistan, Turkmenistan, Ukraine, Uzbekistan) contributed to the medal tally of the USSR.

text:
Summer Games
Winter Games
Combined Total

Team (IOC code)

№

01 !

02 !

03 !

Total

№

01 !

02 !

03 !

Total

№

01 !

02 !

03 !

Total

 Russia (RUS)[16]
6
149
124
153
426
6
47
38
35
120
12
196
162
188
546

 Russia (RUS)(RU1, OAR)[17]
9
150
128
156
434
7
49
44
44
137
16
199
172
200
571

 Soviet Union (URS)[13]
9
395
319
296
1010
9
78
57
59
194
18
473
376
355
1204

 Soviet Union (URS)(EUN)[14]
10
440
357
325
1122
10
87
63
67
217
20
527
420
392
1339

 Russia (RUS)(RU1, OAR)  Soviet Union (URS)(EUN)[18]
19
590
485
481
1556
17
136
107
111
354
36
726
592
592
1910

text: Notes[edit]

text: Obsolete nations notes[edit]

text:
ANZ → AUS , NZL Australasia (ANZ) was a combined team of athletes from Australia (AUS) and New Zealand (NZL). They competed together during the 1908 and 1912 Games.
BOH → TCH → CZE , SVK Prior to the foundation of Czechoslovakia (TCH) after World War I, athletes from Bohemia (BOH) (now part of the present-day Czech Republic) competed in 1900, 1908, and 1912 Games. Czechoslovakia competed in 1920–1992, from 1994 represented by successor NOCs of Czech Republic (CZE) and Slovakia (SVK).
BWI → BAR , JAM , TRI Athletes from Barbados (BAR), Jamaica (JAM), and Trinidad and Tobago (TRI) competed as the British West Indies (BWI) at the 1960 Games. The West Indies Federation only existed as a nation from 1958–1962, so the constituent nations once again competed independently in 1964.
SAA , EUA , GDR , FRG → GER Germany (GER) competed 1896–1952 and from 1992. Due to the partition of Germany after World War II, Germany was represented by two teams at the 1952 Games — Germany (GER) and the Saar (SAA). The Saar was reintegrated back into the Federal Republic of Germany on 1 January 1957, and Saar athletes then competed for Germany. East Germany did not contribute athletes to the 1952 team, as the National Olympic Committee for the German Democratic Republic was only granted "provisional" recognition by the IOC in 1955. For the Games of 1956–1964, Germany participated as a United Team of Germany (EUA), representing the National Olympic Committees of both West Germany and East Germany. Retrospectively, the IOC uses the country code EUA for this team. After the NOC for the German Democratic Republic was granted full recognition by the IOC in 1968, East Germany (GDR) and West Germany (FRG) competed as two independent teams from the 1968 to the 1988 Games.
MAL , NBO → MAS Athletes from Malaya (MAL) and North Borneo (NBO) competed as independent teams at the 1956 Games and Malaya also competed at the 1960 Games, prior to the formation of the Federation of Malaysia (MAS) in 1963.
AHO The Netherlands Antilles (AHO), an autonomous country within the Netherlands (NED), competed 1952–2008. The Netherlands Antilles Olympic Committee's membership in the IOC was withdrawn in 2011 because of the dissolution of the Netherlands Antilles.
RU1 → URS → EUN → RUS Russian Empire (RU1) participated at the 1900, 1908 and 1912 Games prior to the World War I. Soviet Union (URS) competed from 1952 to 1988. Unified Team (EUN) is the generic name used for a combined team of six post-Soviet republics that competed at the 1992 Winter Olympics and a combined team of twelve post-Soviet republics that competed at the 1992 Summer Olympics. Russian Federation (RUS) and the other fourteen post-Soviet republics started competing independently since 1992 (Latvia, Lithuania, Estonia), 1994 or 1996.

SRB , YUG , SCG Serbia (SRB, 1912, 2006-current) first participated at the Olympic Games in 1912. Yugoslavia (YUG, 1920-1992 Winter) competed as Kingdom of Yugoslavia (officially the Kingdom of Serbs, Croats and Slovenes until 1929) in five Games (1920–1936) before the Second World War. They later competed as Socialist Federal Republic of Yugoslavia for the Games (1948–1992 Winter). This ended with the Breakup of Yugoslavia. Some ex-Yugoslavian nations (Croatia, Slovenia, Bosnia and Herzegovina) have competed as independent teams since 1992. Individual athletes from the Federal Republic of Yugoslavia (Serbia and Montenegro) competed as Independent Olympic Participants (IOP) at the 1992 Summer Games because of sanctions placed by the United Nations. Athletes representing Macedonia likewise competed as independent olympic participants because their NOC had not yet been formed. Since 1996 Macedonia has competed as independent team. The combined team Serbia and Montenegro (SCG, 2004-2006) consisted of the Republic of Serbia and the Republic of Montenegro. They competed as Yugoslavia from (YUG, 1996–2002) and then changed to State Union of Serbia and Montenegro (2004–2006). After 96 years Serbia returned to the Olympics as an independent team at the 2008 Games. Montenegro first participated as an independent team in 2008.
YAR , YMD → YEM Prior to Yemeni unification in 1990, North Yemen participated as the Yemen Arab Republic (YAR) in 1984 and 1988, and South Yemen participated as the Yemen Democratic Republic (YMD) at the 1988 Games. After forming united republic Yemen (YEM) has participated since 1992.
ROC → CHN , TPE The Republic of China was designated as China at the 1932, 1936, and 1948 Games and was representing all of China (including Taiwan). After the Chinese Civil War, the People's Republic of China (CHN) and Chinese Taipei (TPE) have participated as separate teams.
ZZX Special code used by the IOC to refer to medals won by athletes of multiple nations competing together, which was common in early Games (1896–1904). These medals are not included in the respective totals for each nation represented by individual mixed team athletes.
IOP , IOA , OAR Special codes used by the IOC for athletes whose NOC is not recognized by IOC. At the 1992 Summer Olympics fifty eight athletes from former Yugoslavia competed as Independent Olympic Participants (IOP). At the 2000 Summer Olympics four athletes from East Timor competed as Individual Olympic Athletes (IOA). At the 2012 Summer Olympics three athletes from former Netherlands Antilles and one athlete from South Sudan competed as Independent Olympic Athletes (IOA). At the 2014 Winter Olympics three athletes from India competed as Independent Olympic Participants (IOP). At the 2016 Summer Olympics nine athletes from Kuwait competed as Independent Olympic Athletes (IOA). At the 2018 Winter Olympics one hundred sixty eight athletes from Russia competed as Olympics Athletes from Russia (OAR).

text: Name changes notes[edit]

text:
BIZ Belize participated under its former name of British Honduras (HBR) in 1968 and 1972.
BEN Benin was known as Dahomey (DAH) in 1972.
BUR Burkina Faso was known as Upper Volta (VOL) in 1972.
TPE2 After the Chinese Civil War, Chinese Taipei (TPE) participated using the name of the Republic of China at the 1956, 1960, 1972 and 1976 (winter) Games and using Taiwan designation at the 1964 and 1968 Games. In 1979, the IOC started to use Chinese Taipei to refer to the NOC, a compromise that was acceptable for the People's Republic of China (CHN) that led to the start of its participation in the Olympic Games. The name Chinese Taipei was first used in 1984. Participation of the Republic of China, representing all of China (including Taiwan), in 1932, 1936 and 1948 Games are not counted in Taiwan's total participation count.
COD The Democratic Republic of the Congo was known as Zaire (ZAI) between 1984 and 1996.
CIV Côte d'Ivoire was known as Ivory Coast between 1964 and 1988.
EGY Egypt participated as the United Arab Republic (UAR) between 1960 and 1968.
GBR Includes medals won by athletes from the United Kingdom of Great Britain and Ireland (1896–1920) and the United Kingdom of Great Britain and Northern Ireland (1924–present), both of which used the name "Great Britain" and the country code GBR.

GHA Prior to Ghana's independence in 1957, Gold Coast participated in the 1952 Games.
GUY Prior to Guyana's independence in 1966, British Guiana participated from 1948 to 1964.
HKG Totals of Hong Kong (HKG) includes all medals won by athletes representing the Hong Kong National Olympic Committee, designated as "Hong Kong" from 1952–1996 and "Hong Kong, China" since 2000.
MYA Myanmar was known as Burma (BIR) between 1948 and 1988.
SAM Samoa was known as Western Samoa between 1984 and 1996.
SRI Sri Lanka was known as Ceylon (CEY) between 1948 and 1972.
TAN Although Tanganyika and Zanzibar had already merged to form Tanzania in April 1964, the nation was designated Tanganyika in the official report of the 1964 Games.
ZAM Zambia achieved independence on the last day of the 1964 Games, but had participated as Northern Rhodesia (NRH) during those Games.
ZIM Prior to Zimbabwe's independence in 1980, Southern Rhodesia participated as Rhodesia (RHO) in 1928, 1960, and 1964 Games.

text: Participation notes[edit]

text:
A Brunei's participation in the 1988 Games consisted only of a single official, but no competing athletes. This participation is not counted in Brunei's participation total.
B Djibouti at the 2004 Games took part in the Opening Ceremony, but neither athlete competed, so this participation is not counted in Djibouti's participation total.
C Liberia's athletes withdrew from 1980 Games after marching in the Opening Ceremony and took part in the boycott. This participation is not counted in Liberia's participation total.
D Libya marched in the opening ceremony of the 1964 Games, but then withdrew from competition. This participation is not counted in Libya's participation total.
E Suriname at the 1960 Games took part in the Opening Ceremony, but its lone athlete withdrew from Games due to a scheduling error. Participation of Suriname at the 1960 Games not recognized by IOC, so this participation is not counted in Suriname's participation total.

F India's athletes originally competed at the 2014 Games as Independent Olympic Participants and marched under the Olympic Flag during the opening ceremony due to the Indian Olympic Association's suspension. On February 11, 2014, the Indian Olympic Association was reinstated and India's athletes were allowed the option to compete under their own flag from that time onward.
Ia Ib Does not include the participation of Timor-Leste's and Netherlands Antilles's athletes as Individual Olympic Athletes (IOA) at the 2000 Summer Olympics and the 2012 Summer Olympics.
Za Zb Zc Zd Ze Zf Zg Zh Zi Zj Zk Zl Zm Does not include medals won as part of mixed teams with athletes from other nations (1896–1904).

text: Disputed participation notes[edit]

text:
H The Bulgarian Olympic Committee claims that Charles Champaud, a Swiss gymnastics teacher living in Sofia, competed for the nation in 1896. Bulgarian participation at the 1896 Games is recognized by the IOC.
I The Chilean Olympic Committee claims that Luis Subercaseaux Errázuriz, a Chilean diplomat and athlete, competed for the nation in 1896. Chilean participation at the 1896 Games is recognized by the IOC.
J Some sources consider Léon Thiércelin, a fencer who competed at the 1900 Games, of Haitian nationality and therefore the first Olympic appearance by Haiti. Participation of Haiti at the 1900 Games is not recognized by the IOC, so this participation is not counted in Haiti's participation total.
K Some sources consider Freydoun Malkom, a fencer who competed at the 1900 Games, of Persian nationality and therefore the first Olympic appearance by Iran. Participation of Iran at the 1900 Games is not recognized by the IOC, so this participation is not counted in Iran's participation total.
L Some sources consider Carlos de Candamo, a fencer who competed at the 1900 Games, of Peruvian nationality and therefore the first Olympic appearance by Peru. Participation of Peru at the 1900 Games is not recognized by the IOC, so this participation is not counted in Peru's participation total.
M Enrico Brusoni's gold medal in the Cycling Men's Points Race at the 1900 Summer Olympics[19] is recognized by the Italian National Olympic Committee as well as the IOC[20] as being won in a 1900 Summer Olympics event, although some sources state it was unofficial.[21]
N Monaco earned a bronze in the art competitions at the 1924 Summer Olympics.[22] However, medals in art competitions are no longer recognized by the IOC.[23]
Oa Ob Michel Théato, a French athlete who won the gold medal in marathon at the 1900 Games, was born in Luxembourg.[3] The IOC does not recognize Luxembourg participation at the 1900 Games and attributes his medal to France.

The nationalities of many medalists at the 1904 Olympics are disputed as many competitors were recent immigrants to the United States who had not yet been granted US citizenship.

Pa Pb Sources are inconsistent regarding Albert Corey's participation in 1904. Although the Games report refers to Corey as a "Frenchman wearing the colors of the Chicago Athletic Association", the IOC attributes his medal in the marathon to the United States instead of France, and in contradiction, the medal in the four mile team race (that was won by a team of three Americans and Corey) to a mixed team composed of athletes from multiple nations instead of just the United States.
Qa Qb The International Olympic Committee considers Norwegian-American wrestlers Charles Ericksen and Bernhoff Hansen to have competed for the United States; each won a gold medal. In 2012, Norwegian historians however found documentation showing that Ericksen did not receive American citizenship until March 22, 1905, and that Hansen, who was registered as an "alien" as late as 1925, probably never received American citizenship. The historians have therefore petitioned to have the athletes registered as Norwegians.[24][25] In May 2013 it was reported that the Norwegian Olympic Committee had filed a formal application for changing the nationality of the wrestlers in IOC's medal database.[26]
R Bob Fowler, an American marathon runner who competed at the 1904 Games, was a native Newfoundlander, Newfoundland is occasionally listed as a separate country at the 1904 Olympics, and would be listed as an historical NOC without medals.[6] Participation of Newfoundland at the 1904 Games is not recognized by the IOC.
S In 2009, historians from the International Society of Olympic Historians discovered that cyclist Frank Bizzoni formerly thought to be an American athlete was still an Italian citizen when he competed in 1904 being granted US citizenship in 1917.[27][28]


document_title: History of nuclear weapons

question_text: who came up with the idea of an atomic bomb

question_tokens: who came up with the idea of an atomic bomb

root

text: History of nuclear weapons

text: Physics and politics in the 1930s and 1940s[edit]

text: In the first decades of the 20th century, physics was revolutionised with developments in the understanding of the nature of atoms. In 1898, Pierre and Marie Curie discovered that pitchblende, an ore of uranium, contained a substance—which they named radium—that emitted large amounts of radioactivity. Ernest Rutherford and Frederick Soddy identified that atoms were breaking down and turning into different elements. Hopes were raised among scientists and laymen that the elements around us could contain tremendous amounts of unseen energy, waiting to be harnessed.

tag: p

text: H. G. Wells was inspired to write about atomic weapons in a 1914 novel, The World Set Free, which appeared shortly before the First World War. In a 1924 article, Winston Churchill speculated about the possible military implications: "Might not a bomb no bigger than an orange be found to possess a secret power to destroy a whole block of buildings—nay to concentrate the force of a thousand tons of cordite and blast a township at a stroke?"[1]

text: In January 1933, Adolf Hitler was appointed Chancellor of Germany and it quickly became unsafe for Jewish scientists to remain in the country. Leó Szilárd fled to London where he proposed, and in 1934 patented, the idea of a nuclear chain reaction via neutrons. The patent also introduced the term critical mass to describe the minimum amount of material required to sustain the chain reaction and its potential to cause an explosion. (British patent 630,726.) He subsequently assigned the patent to the British Admiralty so that it could be covered by the Official Secrets Act.[2] In a very real sense, Szilárd was the father of the atomic bomb academically. Also in 1934, Irène and Frédéric Joliot-Curie discovered that artificial radioactivity could be induced in stable elements by bombarding them with alpha particles; Enrico Fermi reported similar results when bombarding uranium with neutrons.

text: In December 1938, Otto Hahn and Fritz Strassmann sent a manuscript to Naturwissenschaften reporting that they had detected the element barium after bombarding uranium with neutrons.[3] Lise Meitner and her nephew Otto Robert Frisch correctly interpreted these results as being due to the splitting of the uranium atom. (Frisch confirmed this experimentally on January 13, 1939.[4]) They gave the process the name "fission" because of its similarity to the splitting of a cell into two new cells.[5] Even before it was published, news of Meitner’s and Frisch’s interpretation crossed the Atlantic.[6] Scientists at Columbia University decided to replicate the experiment and on January 25, 1939, conducted the first nuclear fission experiment in the United States[7] in the basement of Pupin Hall.[8] The following year, they identified the active component of uranium as being the rare isotope uranium-235.[9]

text: Uranium appears in nature primarily in two isotopes: uranium-238 and uranium-235. When the nucleus of uranium-235 absorbs a neutron, it undergoes nuclear fission, releasing energy and, on average, 2.5 neutrons. Because uranium-235 releases more neutrons than it absorbs, it can support a chain reaction and so is described as fissile. Uranium-238, on the other hand, is not fissile as it does not normally undergo fission when it absorbs a neutron.

text: By the time Nazi Germany invaded Poland in 1939, beginning World War II, many of Europe's top scientists had already fled the imminent conflict. Physicists on both sides were well aware of the possibility of utilizing nuclear fission as a weapon, but no one was quite sure how it could be done. In August 1939, concerned that Germany might have its own project to develop fission-based weapons, Albert Einstein signed a letter to U.S. President Franklin D. Roosevelt warning him of the threat.[10] Roosevelt responded by setting up the Uranium Committee under Lyman James Briggs but, with little initial funding ($6,000), progress was slow. It was not until the Japanese attack on Pearl Harbor in December, 1941, that the U.S. decided to commit the necessary resources.[11]

text: Organized research first began in Britain as part of the Tube Alloys project. The Maud Committee was set up following the work of Frisch and Rudolf Peierls who calculated uranium-235's critical mass and found it to be much smaller than previously thought which meant that a deliverable bomb should be possible.[12] In the February 1940 Frisch–Peierls memorandum they stated that: "The energy liberated in the explosion of such a super-bomb...will, for an instant, produce a temperature comparable to that of the interior of the sun. The blast from such an explosion would destroy life in a wide area. The size of this area is difficult to estimate, but it will probably cover the centre of a big city."

text: Edgar Sengier, a director of Shinkolobwe Mine in the Congo which produced by far the highest quality uranium ore in the world, had become aware of uranium's possible use in a bomb. In late 1940, fearing that it might be seized by the Germans, he shipped the mine's entire stockpile of ore to a warehouse on Staten Island.[13]

text: For 18 months British research outpaced the American but by mid-1942, it became apparent that the industrial effort required was beyond Britain's already stretched wartime economy.[14]:204 In September 1942, General Leslie Groves was appointed to lead the U.S. project which became known as the Manhattan Project. Two of his first acts were to obtain authorization to assign the highest priority AAA rating on necessary procurements, and to order the purchase of all 1,250 tons of the Shinkolobwe ore.[13][15] The Tube Alloys project was quickly overtaken by the U.S. effort[14] and after Roosevelt and Churchill signed the Quebec Agreement in 1943, it was relocated and amalgamated into the Manhattan Project.

text: From Los Alamos to Hiroshima[edit]

text: With a scientific team led by J. Robert Oppenheimer, the Manhattan project brought together some of the top scientific minds of the day, including many exiles from Europe, with the production power of American industry for the goal of producing fission-based explosive devices before Germany. Britain and the U.S. agreed to pool their resources and information for the project, but the other Allied power, the Soviet Union (USSR), was not informed. The U.S. made an unprecedented investment in the project which at the time was the largest industrial enterprise ever seen,[14] spread across more than 30 sites in the U.S. and Canada. Scientific development was centralized in a secret laboratory at Los Alamos.

text: For a fission weapon to operate, there must be sufficient fissile material to support a chain reaction, a critical mass. To separate the fissile uranium-235 isotope from the non-fissile uranium-238, two methods were developed which took advantage of the fact that uranium-238 has a slightly greater atomic mass: electromagnetic separation and gaseous diffusion. Another secret site was erected at rural Oak Ridge, Tennessee, for the large-scale production and purification of the rare isotope, which required considerable investment. At the time, K-25, one of the Oak Ridge facilities, was the world's largest factory under one roof. The Oak Ridge site employed tens of thousands of people at its peak, most of whom had no idea what they were working on.

text: Although uranium-238 cannot be used for the initial stage of an atomic bomb, when it absorbs a neutron, it becomes uranium-239 which decays into neptunium-239, and finally the relatively stable plutonium-239, an element that does not exist naturally on Earth, but is fissile like uranium-235. After Fermi achieved the world's first sustained and controlled nuclear chain reaction with the creation of the first atomic pile, massive reactors were secretly constructed at what is now known as Hanford Site to transform uranium-238 into plutonium for a bomb.

text: The simplest form of nuclear weapon is a gun-type fission weapon, where a sub-critical mass would be shot at another sub-critical mass. The result would be a super-critical mass and an uncontrolled chain reaction that would create the desired explosion. The weapons envisaged in 1942 were the two gun-type weapons, Little Boy (uranium) and Thin Man (plutonium), and the Fat Man plutonium implosion bomb.

text: In early 1943 Oppenheimer determined that two projects should proceed forwards: the Thin Man project (plutonium gun) and the Fat Man project (plutonium implosion). The plutonium gun was to receive the bulk of the research effort, as it was the project with the most uncertainty involved. It was assumed that the uranium gun-type bomb could then be adapted from it.

text: In December 1943 the British mission of 19 scientists arrived in Los Alamos. Hans Bethe became head of the Theoretical Division.

text: In April 1944 it was found by Emilio Segrè that the plutonium-239 produced by the Hanford reactors had too high a level of background neutron radiation, and underwent spontaneous fission to a very small extent, due to the unexpected presence of plutonium-240 impurities. If such plutonium were used in a gun-type design, the chain reaction would start in the split second before the critical mass was fully assembled, blowing the weapon apart with a much lower yield than expected, in what is known as a fizzle.

text: As a result, development of Fat Man was given high priority. Chemical explosives were used to implode a sub-critical sphere of plutonium, thus increasing its density and making it into a critical mass. The difficulties with implosion centered on the problem of making the chemical explosives deliver a perfectly uniform shock wave upon the plutonium sphere— if it were even slightly asymmetric, the weapon would fizzle. This problem was solved by the use of explosive lenses which would focus the blast waves inside the imploding sphere, akin to the way in which an optical lens focuses light rays.[16]

text: After D-Day, General Groves ordered a team of scientists to follow eastward-moving victorious Allied troops into Europe to assess the status of the German nuclear program (and to prevent the westward-moving Soviets from gaining any materials or scientific manpower). They concluded that, while Germany had an atomic bomb program headed by Werner Heisenberg, the government had not made a significant investment in the project, and it had been nowhere near success.[citation needed] Similarly, Japan's efforts at developing a nuclear weapon were starved of resources. The Japanese navy lost interest when a committee led by Yoshio Nishina concluded in 1943 that "it would probably be difficult even for the United States to realize the application of atomic power during the war".[17]

text: Historians claim to have found a rough schematic showing a Nazi nuclear bomb.[18] In March 1945, a German scientific team was directed by the physicist Kurt Diebner to develop a primitive nuclear device in Ohrdruf, Thuringia.[18][19] Last ditch research was conducted in an experimental nuclear reactor at Haigerloch.

text: On April 12, after Roosevelt's death, Vice-President Harry S. Truman assumed the presidency. At the time of the unconditional surrender of Germany on May 8, 1945, the Manhattan Project was still months away from producing a working weapon.

text: Because of the difficulties in making a working plutonium bomb, it was decided that there should be a test of the weapon. On July 16, 1945, in the desert north of Alamogordo, New Mexico, the first nuclear test took place, code-named "Trinity", using a device nicknamed "the gadget." The test, a plutonium implosion type device, released energy equivalent to 19 kilotons of TNT, far more powerful than any weapon ever used before. The news of the test's success was rushed to Truman at the Potsdam Conference, where Churchill was briefed and Soviet Premier Joseph Stalin was informed of the new weapon. On July 26, the Potsdam Declaration was issued containing an ultimatum for Japan: either surrender or suffer "complete and utter destruction", although nuclear weapons were not mentioned.[14]

text: After hearing arguments from scientists and military officers over the possible use of nuclear weapons against Japan (though some recommended using them as demonstrations in unpopulated areas, most recommended using them against built up targets, a euphemistic term for populated cities), Truman ordered the use of the weapons on Japanese cities, hoping it would send a strong message that would end in the capitulation of the Japanese leadership and avoid a lengthy invasion of the islands. On May 10–11, 1945, the Target Committee at Los Alamos, led by Oppenheimer, recommended Kyoto, Hiroshima, Yokohama, and Kokura as possible targets. Concerns about Kyoto's cultural heritage led to it being replaced by Nagasaki.

text: On August 6, 1945, a uranium-based weapon, Little Boy, was detonated above the Japanese city of Hiroshima, and three days later, a plutonium-based weapon, Fat Man, was detonated above the Japanese city of Nagasaki. To date, Hiroshima and Nagasaki remain the only two instances of nuclear weapons being used in combat. The atomic raids killed at least one hundred thousand Japanese civilians and military personnel outright, with the heat, radiation, and blast effects. Many tens of thousands would later die of radiation sickness and related cancers.[20][21] Truman promised a "rain of ruin" if Japan did not surrender immediately, threatening to systematically eliminate their ability to wage war.[22] On August 15, Emperor Hirohito announced Japan's surrender.[23]

text: Soviet atomic bomb project[edit]

text: The Soviet Union was not invited to share in the new weapons developed by the United States and the other Allies. During the war, information had been pouring in from a number of volunteer spies involved with the Manhattan Project (known in Soviet cables under the code-name of Enormoz), and the Soviet nuclear physicist Igor Kurchatov was carefully watching the Allied weapons development. It came as no surprise to Stalin when Truman had informed him at the Potsdam conference that he had a "powerful new weapon." Truman was shocked at Stalin's lack of interest.

text: The Soviet spies in the U.S. project were all volunteers and none were Soviet citizens. One of the most valuable, Klaus Fuchs, was a German émigré theoretical physicist who had been part of the early British nuclear efforts and the UK mission to Los Alamos. Fuchs had been intimately involved in the development of the implosion weapon, and passed on detailed cross-sections of the Trinity device to his Soviet contacts. Other Los Alamos spies—none of whom knew each other—included Theodore Hall and David Greenglass. The information was kept but not acted upon, as the Soviet Union was still too busy fighting the war in Europe to devote resources to this new project.

text: In the years immediately after World War II, the issue of who should control atomic weapons became a major international point of contention. Many of the Los Alamos scientists who had built the bomb began to call for "international control of atomic energy," often calling for either control by transnational organizations or the purposeful distribution of weapons information to all superpowers, but due to a deep distrust of the intentions of the Soviet Union, both in postwar Europe and in general, the policy-makers of the United States worked to attempt to secure an American nuclear monopoly.

text: A half-hearted plan for international control was proposed at the newly formed United Nations by Bernard Baruch (The Baruch Plan), but it was clear both to American commentators—and to the Soviets—that it was an attempt primarily to stymie Soviet nuclear efforts. The Soviets vetoed the plan, effectively ending any immediate postwar negotiations on atomic energy, and made overtures towards banning the use of atomic weapons in general.

text: The Soviets had put their full industrial might and manpower into the development of their own atomic weapons. The initial problem for the Soviets was primarily one of resources—they had not scouted out uranium resources in the Soviet Union and the U.S. had made deals to monopolise the largest known (and high purity) reserves in the Belgian Congo. The USSR used penal labour to mine the old deposits in Czechoslovakia—now an area under their control—and searched for other domestic deposits (which were eventually found).

text: Two days after the bombing of Nagasaki, the U.S. government released an official technical history of the Manhattan Project, authored by Princeton physicist Henry DeWolf Smyth, known colloquially as the Smyth Report. The sanitized summary of the wartime effort focused primarily on the production facilities and scale of investment, written in part to justify the wartime expenditure to the American public.

text: The Soviet program, under the suspicious watch of former NKVD chief Lavrenty Beria (a participant and victor in Stalin's Great Purge of the 1930s), would use the Report as a blueprint, seeking to duplicate as much as possible the American effort. The "secret cities" used for the Soviet equivalents of Hanford and Oak Ridge literally vanished from the maps for decades to come.

text: At the Soviet equivalent of Los Alamos, Arzamas-16, physicist Yuli Khariton led the scientific effort to develop the weapon. Beria distrusted his scientists, however, and he distrusted the carefully collected espionage information. As such, Beria assigned multiple teams of scientists to the same task without informing each team of the other's existence. If they arrived at different conclusions, Beria would bring them together for the first time and have them debate with their newfound counterparts. Beria used the espionage information as a way to double-check the progress of his scientists, and in his effort for duplication of the American project even rejected more efficient bomb designs in favor of ones that more closely mimicked the tried-and-true Fat Man bomb used by the U.S. against Nagasaki.

text: Working under a stubborn and scientifically ignorant administrator, the Soviet scientists struggled on. On August 29, 1949, the effort brought its results, when the USSR tested its first fission bomb, dubbed "Joe-1" by the U.S., years ahead of American predictions. The news of the first Soviet bomb was announced to the world first by the United States, which had detected the nuclear fallout it generated from its test site in Kazakhstan.

text: The loss of the American monopoly on nuclear weapons marked the first tit-for-tat of the nuclear arms race. The response in the U.S. was one of apprehension, fear, and scapegoating, which would lead eventually into the Red-baiting tactics of McCarthyism. Yet recent information from unclassified Venona intercepts and the opening of the KGB archives after the fall of the Soviet Union show that the USSR had useful spies that helped their program, although none were identified by McCarthy.[citation needed] Before this, though, President Truman announced a decision to begin a crash program that would develop a far more powerful weapon than those the U.S. used against Japan: the hydrogen bomb.

text: American developments after World War II[edit]

text: In 1946 Congress established the civilian Atomic Energy Commission (AEC) to take over the development of nuclear weapons from the military, and to develop nuclear power. The AEC made use of many private companies in processing uranium and thorium and in other urgent tasks related to the development of bombs. Many of these companies had very lax safety measures and employees were sometimes exposed to radiation levels far above what was allowed then or now.[24] In 1974, the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the Army Corps of Engineers was set up to deal with contaminated sites left over from these operations.[25]

text: The first thermonuclear weapons[edit]

text: The notion of using a fission weapon to ignite a process of nuclear fusion can be dated back to 1942. At the first major theoretical conference on the development of an atomic bomb hosted by J. Robert Oppenheimer at the University of California, Berkeley, participant Edward Teller directed the majority of the discussion towards Enrico Fermi's idea of a "Super" bomb that would use the same reactions that powered the Sun itself.

text: It was thought at the time that a fission weapon would be quite simple to develop and that perhaps work on a hydrogen bomb (thermonuclear weapon) would be possible to complete before the end of the Second World War. However, in reality the problem of a regular atomic bomb was large enough to preoccupy the scientists for the next few years, much less the more speculative "Super" bomb. Only Teller continued working on the project—against the will of project leaders Oppenheimer and Hans Bethe.

text: After the atomic bombings of Japan, many scientists at Los Alamos rebelled against the notion of creating a weapon thousands of times more powerful than the first atomic bombs. For the scientists the question was in part technical—the weapon design was still quite uncertain and unworkable—and in part moral: such a weapon, they argued, could only be used against large civilian populations, and could thus only be used as a weapon of genocide.

text: Many scientists, such as Bethe, urged that the United States should not develop such weapons and set an example towards the Soviet Union. Promoters of the weapon, including Teller, Ernest Lawrence, and Luis Alvarez, argued that such a development was inevitable, and to deny such protection to the people of the United States—especially when the Soviet Union was likely to create such a weapon themselves—was itself an immoral and unwise act.

text: Oppenheimer, who was now head of the General Advisory Committee of the successor to the Manhattan Project, the Atomic Energy Commission, presided over a recommendation against the development of the weapon. The reasons were in part because the success of the technology seemed limited at the time (and not worth the investment of resources to confirm whether this was so), and because Oppenheimer believed that the atomic forces of the United States would be more effective if they consisted of many large fission weapons (of which multiple bombs could be dropped on the same targets) rather than the large and unwieldy super bombs, for which there was a relatively limited number of targets of sufficient size to warrant such a development.

text: What is more, if such weapons were developed by both superpowers, they would be more effective against the U.S. than against the USSR, as the U.S. had far more regions of dense industrial and civilian activity as targets for large weapons than the Soviet Union.

text: In the end, President Truman made the final decision, looking for a proper response to the first Soviet atomic bomb test in 1949. On January 31, 1950, Truman announced a crash program to develop the hydrogen (fusion) bomb. At this point, however, the exact mechanism was still not known: the classical hydrogen bomb, whereby the heat of the fission bomb would be used to ignite the fusion material, seemed highly unworkable. However, an insight by Los Alamos mathematician Stanislaw Ulam showed that the fission bomb and the fusion fuel could be in separate parts of the bomb, and that radiation of the fission bomb could first work in a way to compress the fusion material before igniting it.

text: Teller pushed the notion further, and used the results of the boosted-fission "George" test (a boosted-fission device using a small amount of fusion fuel to boost the yield of a fission bomb) to confirm the fusion of heavy hydrogen elements before preparing for their first true multi-stage, Teller-Ulam hydrogen bomb test. Many scientists, initially against the weapon, such as Oppenheimer and Bethe, changed their previous opinions, seeing the development as being unstoppable.

text: The first fusion bomb was tested by the United States in Operation Ivy on November 1, 1952, on Elugelab Island in the Enewetak (or Eniwetok) Atoll of the Marshall Islands, code-named "Mike." Mike used liquid deuterium as its fusion fuel and a large fission weapon as its trigger. The device was a prototype design and not a deliverable weapon: standing over 20 ft (6 m) high and weighing at least 140,000 lb (64 t) (its refrigeration equipment added an additional 24,000 lb (11,000 kg) as well), it could not have been dropped from even the largest planes.

text: Its explosion yielded energy equivalent to 10.4 megatons of TNT—over 450 times the power of the bomb dropped onto Nagasaki— and obliterated Elugelab, leaving an underwater crater 6240 ft (1.9 km) wide and 164 ft (50 m) deep where the island had once been. Truman had initially tried to create a media blackout about the test—hoping it would not become an issue in the upcoming presidential election—but on January 7, 1953, Truman announced the development of the hydrogen bomb to the world as hints and speculations of it were already beginning to emerge in the press.

text: Not to be outdone, the Soviet Union exploded its first thermonuclear device, designed by the physicist Andrei Sakharov, on August 12, 1953, labeled "Joe-4" by the West. This created concern within the U.S. government and military, because, unlike Mike, the Soviet device was a deliverable weapon, which the U.S. did not yet have. This first device though was arguably not a true hydrogen bomb, and could only reach explosive yields in the hundreds of kilotons (never reaching the megaton range of a staged weapon). Still, it was a powerful propaganda tool for the Soviet Union, and the technical differences were fairly oblique to the American public and politicians.

text: Following the Mike blast by less than a year, Joe-4 seemed to validate claims that the bombs were inevitable and vindicate those who had supported the development of the fusion program. Coming during the height of McCarthyism, the effect was pronounced on the security hearings in early 1954, which revoked former Los Alamos director Robert Oppenheimer's security clearance on the grounds that he was unreliable, had not supported the American hydrogen bomb program, and had made long-standing left-wing ties in the 1930s. Edward Teller participated in the hearing as the only major scientist to testify against Oppenheimer, resulting in his virtual expulsion from the physics community.

text: On March 1, 1954, the U.S. detonated its first practical thermonuclear weapon (which used isotopes of lithium as its fusion fuel), known as the "Shrimp" device of the Castle Bravo test, at Bikini Atoll, Marshall Islands. The device yielded 15 megatons, more than twice its expected yield, and became the worst radiological disaster in U.S. history. The combination of the unexpectedly large blast and poor weather conditions caused a cloud of radioactive nuclear fallout to contaminate over 7,000 square miles (18,000 km2). 239 Marshall Island natives and 28 Americans were exposed to significant amounts of radiation, resulting in elevated levels of cancer and birth defects in the years to come.[26]

text: The crew of the Japanese tuna-fishing boat Lucky Dragon 5, who had been fishing just outside the exclusion zone, returned to port suffering from radiation sickness and skin burns; one crew member was terminally ill. Efforts were made to recover the cargo of contaminated fish but at least two large tuna were probably sold and eaten. A further 75 tons of tuna caught between March and December were found to be unfit for human consumption. When the crew member died and the full results of the contamination were made public by the U.S., Japanese concerns were reignited about the hazards of radiation.[27]

text: The hydrogen bomb age had a profound effect on the thoughts of nuclear war in the popular and military mind. With only fission bombs, nuclear war was something that possibly could be limited. Dropped by planes and only able to destroy the most built up areas of major cities, it was possible for many to look at fission bombs as a technological extension of large-scale conventional bombing—such as the extensive firebombing of German and Japanese cities during World War II. Proponents brushed aside as grave exaggeration claims that such weapons could lead to worldwide death or harm.

text: Even in the decades before fission weapons, there had been speculation about the possibility for human beings to end all life on the planet, either by accident or purposeful maliciousness—but technology had not provided the capacity for such action. The great power of hydrogen bombs made worldwide annihilation possible.

text: The Castle Bravo incident itself raised a number of questions about the survivability of a nuclear war. Government scientists in both the U.S. and the USSR had insisted that fusion weapons, unlike fission weapons, were cleaner, as fusion reactions did not produce the dangerously radioactive by-products of fission reactions. While technically true, this hid a more gruesome point: the last stage of a multi-staged hydrogen bomb often used the neutrons produced by the fusion reactions to induce fissioning in a jacket of natural uranium, and provided around half of the yield of the device itself.

text: This fission stage made fusion weapons considerably more dirty than they were made out to be. This was evident in the towering cloud of deadly fallout that followed the Bravo test. When the Soviet Union tested its first megaton device in 1955, the possibility of a limited nuclear war seemed even more remote in the public and political mind. Even cities and countries that were not direct targets would suffer fallout contamination. Extremely harmful fission products would disperse via normal weather patterns and embed in soil and water around the planet.

text: Speculation began to run towards what fallout and dust from a full-scale nuclear exchange would do to the world as a whole, rather than just cities and countries directly involved. In this way, the fate of the world was now tied to the fate of the bomb-wielding superpowers.

text: Deterrence and brinkmanship[edit]

text: Throughout the 1950s and the early 1960s the U.S. and the USSR both endeavored, in a tit-for-tat approach, to prevent the other power from acquiring nuclear supremacy. This had massive political and cultural effects during the Cold War.

text: The first atomic bombs dropped on Hiroshima and Nagasaki were large, custom-made devices, requiring highly trained personnel for their arming and deployment. They could be dropped only from the largest bomber planes—at the time the B-29 Superfortress—and each plane could only carry a single bomb in its hold.

text: The first hydrogen bombs were similarly massive and complicated. This ratio of one plane to one bomb was still fairly impressive in comparison with conventional, non-nuclear weapons, but against other nuclear-armed countries it was considered a grave danger. In the immediate postwar years, the U.S. expended much effort on making the bombs "G.I.-proof"—capable of being used and deployed by members of the U.S. Army, rather than Nobel Prize–winning scientists. In the 1950s, the U.S. undertook a nuclear testing program to improve the nuclear arsenal.

text: Starting in 1951, the Nevada Test Site (in the Nevada desert) became the primary location for all U.S. nuclear testing (in the USSR, Semipalatinsk Test Site in Kazakhstan served a similar role). Tests were divided into two primary categories: "weapons related" (verifying that a new weapon worked or looking at exactly how it worked) and "weapons effects" (looking at how weapons behaved under various conditions or how structures behaved when subjected to weapons).

text: In the beginning, almost all nuclear tests were either atmospheric (conducted above ground, in the atmosphere) or underwater (such as some of the tests done in the Marshall Islands). Testing was used as a sign of both national and technological strength, but also raised questions about the safety of the tests, which released nuclear fallout into the atmosphere (most dramatically with the Castle Bravo test in 1954, but in more limited amounts with almost all atmospheric nuclear testing).

text: Because testing was seen as a sign of technological development (the ability to design usable weapons without some form of testing was considered dubious), halts on testing were often called for as stand-ins for halts in the nuclear arms race itself, and many prominent scientists and statesmen lobbied for a ban on nuclear testing. In 1958, the U.S., USSR, and the United Kingdom (a new nuclear power) declared a temporary testing moratorium for both political and health reasons, but by 1961 the Soviet Union had broken the moratorium and both the USSR and the U.S. began testing with great frequency.

text: As a show of political strength, the Soviet Union tested the largest-ever nuclear weapon in October 1961, the massive Tsar Bomba, which was tested in a reduced state with a yield of around 50 megatons—in its full state it was estimated to have been around 100 Mt. The weapon was largely impractical for actual military use, but was hot enough to induce third-degree burns at a distance of 62 mi (100 km) away. In its full, dirty, design it would have increased the amount of worldwide fallout since 1945 by 25%.

text: In 1963, all nuclear and many non-nuclear states signed the Limited Test Ban Treaty, pledging to refrain from testing nuclear weapons in the atmosphere, underwater, or in outer space. The treaty permitted underground tests.

text: Most tests were considerably more modest, and worked for direct technical purposes as well as their potential political overtones. Weapons improvements took on two primary forms. One was an increase in efficiency and power, and within only a few years fission bombs were developed that were many times more powerful than the ones created during World War II. The other was a program of miniaturization, reducing the size of the nuclear weapons.

text: Smaller bombs meant that bombers could carry more of them, and also that they could be carried on the new generation of rockets in development in the 1950s and 1960s. U.S. rocket science received a large boost in the postwar years, largely with the help of engineers acquired from the Nazi rocketry program. These included scientists such as Wernher von Braun, who had helped design the V-2 rockets the Nazis launched across the English Channel. An American program, Project Paperclip, had endeavored to move German scientists into American hands (and away from Soviet hands) and put them to work for the U.S.

text: Weapons improvement[edit]

text: Early nuclear-tipped rockets—such as the MGR-1 Honest John, first deployed by the U.S. in 1953—were surface-to-surface missiles with relatively short ranges (around 15 mi/25 km maximum) and yields around twice the size of the first fission weapons. The limited range meant they could only be used in certain types of military situations. U.S. rockets could not, for example, threaten Moscow with an immediate strike, and could only be used as tactical weapons (that is, for small-scale military situations).

text: Strategic weapons—weapons that could threaten an entire country—relied, for the time being, on long-range bombers that could penetrate deep into enemy territory. In the U.S., this requirement led, in 1946, to creation of the Strategic Air Command—a system of bombers headed by General Curtis LeMay (who previously presided over the firebombing of Japan during WWII). In operations like Chrome Dome, SAC kept nuclear-armed planes in the air 24 hours a day, ready for an order to attack Moscow.

text: These technological possibilities enabled nuclear strategy to develop a logic considerably different from previous military thinking. Because the threat of nuclear warfare was so awful, it was first thought that it might make any war of the future impossible. President Dwight D. Eisenhower's doctrine of "massive retaliation" in the early years of the Cold War was a message to the USSR, saying that if the Red Army attempted to invade the parts of Europe not given to the Eastern bloc during the Potsdam Conference (such as West Germany), nuclear weapons would be used against the Soviet troops and potentially the Soviet leaders.

text: With the development of more rapid-response technologies (such as rockets and long-range bombers), this policy began to shift. If the Soviet Union also had nuclear weapons and a policy of "massive retaliation" was carried out, it was reasoned, then any Soviet forces not killed in the initial attack, or launched while the attack was ongoing, would be able to serve their own form of nuclear retaliation against the U.S. Recognizing that this was an undesirable outcome, military officers and game theorists at the RAND think tank developed a nuclear warfare strategy that was eventually called Mutually Assured Destruction (MAD).

text: MAD divided potential nuclear war into two stages: first strike and second strike. First strike meant the first use of nuclear weapons by one nuclear-equipped nation against another nuclear-equipped nation. If the attacking nation did not prevent the attacked nation from a nuclear response, the attacked nation would respond with a second strike against the attacking nation. In this situation, whether the U.S. first attacked the USSR or the USSR first attacked the U.S., the end result would be that both nations would be damaged to the point of utter social collapse.

text: According to game theory, because starting a nuclear war was suicidal, no logical country would shoot first. However, if a country could launch a first strike that utterly destroyed the target country's ability to respond, that might give that country the confidence to initiate a nuclear war. The object of a country operating by the MAD doctrine is to deny the opposing country this first strike capability.

text: MAD played on two seemingly opposed modes of thought: cold logic and emotional fear. The English phrase MAD was often known by, "nuclear deterrence," was translated by the French as "dissuasion," and "terrorization" by the Soviets. This apparent paradox of nuclear war was summed up by British Prime Minister Winston Churchill as "the worse things get, the better they are"—the greater the threat of mutual destruction, the safer the world would be.

text: This philosophy made a number of technological and political demands on participating nations. For one thing, it said that it should always be assumed that an enemy nation may be trying to acquire first strike capability, which must always be avoided. In American politics this translated into demands to avoid "bomber gaps" and "missile gaps" where the Soviet Union could potentially outshoot the Americans. It also encouraged the production of thousands of nuclear weapons by both the U.S. and the USSR, far more than needed to simply destroy the major civilian and military infrastructures of the opposing country. These policies and strategies were satirized in the 1964 Stanley Kubrick film Dr. Strangelove, in which the Soviets, unable to keep up with the US's first strike capability, instead plan for MAD by building a Doomsday Machine, and thus, after a (literally) mad US General orders a nuclear attack on the USSR, the end of the world is brought about.

text: The policy also encouraged the development of the first early warning systems. Conventional war, even at its fastest, was fought over days and weeks. With long-range bombers, from the start of a nuclear attack to its conclusion was mere hours. Rockets could reduce a conflict to minutes. Planners reasoned that conventional command and control systems could not adequately react to a nuclear attack, so great lengths were taken to develop computer systems that could look for enemy attacks and direct rapid responses.

text: The U.S. poured massive funding into development of SAGE, a system that could track and intercept enemy bomber aircraft using information from remote radar stations. It was the first computer system to feature real-time processing, multiplexing, and display devices. It was the first general computing machine, and a direct predecessor of modern computers.

text: Emergence of the anti-nuclear movement[edit]

text: The atomic bombings of Hiroshima and Nagasaki and the end of World War II quickly followed the 1945 Trinity nuclear test, and the Little Boy device was detonated over the Japanese city of Hiroshima on 6 August 1945. Exploding with a yield equivalent to 12,500 tonnes of TNT, the blast and thermal wave of the bomb destroyed nearly 50,000 buildings and killed approximately 75,000 people.[28] Subsequently, the world’s nuclear weapons stockpiles grew.[29]

text: Operation Crossroads was a series of nuclear weapon tests conducted by the United States at Bikini Atoll in the Pacific Ocean in the summer of 1946. Its purpose was to test the effect of nuclear weapons on naval ships. To prepare the Bikini atoll for the nuclear tests, Bikini's native residents were evicted from their homes and resettled on smaller, uninhabited islands where they were unable to sustain themselves.[30]

text: National leaders debated the impact of nuclear weapons on domestic and foreign policy. Also involved in the debate about nuclear weapons policy was the scientific community, through professional associations such as the Federation of Atomic Scientists and the Pugwash Conference on Science and World Affairs.[31] Radioactive fallout from nuclear weapons testing was first drawn to public attention in 1954 when a Hydrogen bomb test in the Pacific contaminated the crew of the Japanese fishing boat Lucky Dragon.[32] One of the fishermen died in Japan seven months later. The incident caused widespread concern around the world and "provided a decisive impetus for the emergence of the anti-nuclear weapons movement in many countries".[32] The anti-nuclear weapons movement grew rapidly because for many people the atomic bomb "encapsulated the very worst direction in which society was moving".[33]

text: Peace movements emerged in Japan and in 1954 they converged to form a unified "Japanese Council Against Atomic and Hydrogen Bombs". Japanese opposition to the Pacific nuclear weapons tests was widespread, and "an estimated 35 million signatures were collected on petitions calling for bans on nuclear weapons".[33] The Russell–Einstein Manifesto was issued in London on July 9, 1955 by Bertrand Russell in the midst of the Cold War. It highlighted the dangers posed by nuclear weapons and called for world leaders to seek peaceful resolutions to international conflict. The signatories included eleven pre-eminent intellectuals and scientists, including Albert Einstein, who signed it just days before his death on April 18, 1955. A few days after the release, philanthropist Cyrus S. Eaton offered to sponsor a conference—called for in the manifesto—in Pugwash, Nova Scotia, Eaton's birthplace. This conference was to be the first of the Pugwash Conferences on Science and World Affairs, held in July 1957.

text: In the United Kingdom, the first Aldermaston March organised by the Campaign for Nuclear Disarmament took place at Easter 1958, when several thousand people marched for four days from Trafalgar Square, London, to the Atomic Weapons Research Establishment close to Aldermaston in Berkshire, England, to demonstrate their opposition to nuclear weapons.[34][35] The Aldermaston marches continued into the late 1960s when tens of thousands of people took part in the four-day marches.[33]

text: In 1959, a letter in the Bulletin of the Atomic Scientists was the start of a successful campaign to stop the Atomic Energy Commission dumping radioactive waste in the sea 19 kilometres from Boston.[36] On November 1, 1961, at the height of the Cold War, about 50,000 women brought together by Women Strike for Peace marched in 60 cities in the United States to demonstrate against nuclear weapons. It was the largest national women's peace protest of the 20th century.[37][38]

text: In 1958, Linus Pauling and his wife presented the United Nations with the petition signed by more than 11,000 scientists calling for an end to nuclear-weapon testing. The "Baby Tooth Survey," headed by Dr Louise Reiss, demonstrated conclusively in 1961 that above-ground nuclear testing posed significant public health risks in the form of radioactive fallout spread primarily via milk from cows that had ingested contaminated grass.[39][40][41] Public pressure and the research results subsequently led to a moratorium on above-ground nuclear weapons testing, followed by the Partial Test Ban Treaty, signed in 1963 by John F. Kennedy and Nikita Khrushchev.[31][42][43]

text: Cuban Missile Crisis[edit]

text: Bombers and short-range rockets were not reliable: planes could be shot down, and earlier nuclear missiles could cover only a limited range— for example, the first Soviet rockets' range limited them to targets in Europe. However, by the 1960s, both the United States and the Soviet Union had developed intercontinental ballistic missiles, which could be launched from extremely remote areas far away from their target. They had also developed submarine-launched ballistic missiles, which had less range but could be launched from submarines very close to the target without any radar warning. This made any national protection from nuclear missiles increasingly impractical.

text: The military realities made for a precarious diplomatic situation. The international politics of brinkmanship led leaders to exclaim their willingness to participate in a nuclear war rather than concede any advantage to their opponents, feeding public fears that their generation may be the last. Civil defense programs undertaken by both superpowers, exemplified by the construction of fallout shelters and urging civilians about the survivability of nuclear war, did little to ease public concerns.

text: The climax of brinksmanship came in early 1962, when an American U-2 spy plane photographed a series of launch sites for medium-range ballistic missiles being constructed on the island of Cuba, just off the coast of the southern United States, beginning what became known as the Cuban Missile Crisis. The U.S. administration of John F. Kennedy concluded that the Soviet Union, then led by Nikita Khrushchev, was planning to station Soviet nuclear missiles on the island, which was under the control of communist Fidel Castro. On October 22, Kennedy announced the discoveries in a televised address. He announced a naval blockade around Cuba that would turn back Soviet nuclear shipments, and warned that the military was prepared "for any eventualities." The missiles had 2,400 mile (4,000 km) range, and would allow the Soviet Union to quickly destroy many major American cities on the Eastern Seaboard if a nuclear war began.

text: The leaders of the two superpowers stood nose to nose, seemingly poised over the beginnings of a third world war. Khrushchev's ambitions for putting the weapons on the island were motivated in part by the fact that the U.S. had stationed similar weapons in Britain, Italy, and nearby Turkey, and had previously attempted to sponsor an invasion of Cuba the year before in the failed Bay of Pigs Invasion. On October 26, Khrushchev sent a message to Kennedy offering to withdraw all missiles if Kennedy committed to a policy of no future invasions of Cuba. Khrushchev worded the threat of assured destruction eloquently:

text: "You and I should not now pull on the ends of the rope in which you have tied a knot of war, because the harder you and I pull, the tighter the knot will become. And a time may come when this knot is tied so tight that the person who tied it is no longer capable of untying it, and then the knot will have to be cut. What that would mean I need not explain to you, because you yourself understand perfectly what dreaded forces our two countries possess."

text: A day later, however, the Soviets sent another message, this time demanding that the U.S. remove its missiles from Turkey before any missiles were withdrawn from Cuba. On the same day, a U-2 plane was shot down over Cuba and another almost intercepted over the Soviet Union, as Soviet merchant ships neared the quarantine zone. Kennedy responded by accepting the first deal publicly, and sending his brother Robert to the Soviet embassy to accept the second deal privately. On October 28, the Soviet ships stopped at the quarantine line and, after some hesitation, turned back towards the Soviet Union. Khrushchev announced that he had ordered the removal of all missiles in Cuba, and U.S. Secretary of State Dean Rusk was moved to comment, "We went eyeball to eyeball, and the other fellow just blinked."

text: The Crisis was later seen as the closest the U.S. and the USSR ever came to nuclear war and had been narrowly averted by last-minute compromise by both superpowers. Fears of communication difficulties led to the installment of the first hotline, a direct link between the superpowers that allowed them to more easily discuss future military activities and political maneuverings. It had been made clear that missiles, bombers, submarines, and computerized firing systems made escalating any situation to Armageddon far more easy than anybody desired.

text: After stepping so close to the brink, both the U.S. and the USSR worked to reduce their nuclear tensions in the years immediately following. The most immediate culmination of this work was the signing of the Partial Test Ban Treaty in 1963, in which the U.S. and USSR agreed to no longer test nuclear weapons in the atmosphere, underwater, or in outer space. Testing underground continued, allowing for further weapons development, but the worldwide fallout risks were purposefully reduced, and the era of using massive nuclear tests as a form of saber rattling ended.

text: In December 1979, NATO decided to deploy cruise and Pershing II missiles in Western Europe in response to Soviet deployment of intermediate range mobile missiles, and in the early 1980s, a "dangerous Soviet-US nuclear confrontation" arose.[44] In New York on June 12, 1982, one million people gathered to protest about nuclear weapons, and to support the second UN Special Session on Disarmament.[45][46] As the nuclear abolitionist movement grew, there were many protests at the Nevada Test Site. For example, on February 6, 1987, nearly 2,000 demonstrators, including six members of Congress, protested against nuclear weapons testing and more than 400 people were arrested.[47] Four of the significant groups organizing this renewal of anti-nuclear activism were Greenpeace, The American Peace Test, The Western Shoshone, and Nevada Desert Experience.

text: There have been at least four major false alarms, the most recent in 1995, that resulted in the activation of nuclear attack early warning protocols. They include the accidental loading of a training tape into the American early-warning computers; a computer chip failure that appeared to show a random number of attacking missiles; a rare alignment of the Sun, the U.S. missile fields and a Soviet early-warning satellite that caused it to confuse high-altitude clouds with missile launches; the launch of a Norwegian research rocket resulted in President Yeltsin activating his nuclear briefcase for the first time.[48]

text: Initial proliferation[edit]

text: In the fifties and sixties, three more countries joined the "nuclear club." The United Kingdom had been an integral part of the Manhattan Project following the Quebec Agreement in 1943. The passing of the McMahon Act by the United States in 1946 unilaterally broke this partnership and prevented the passage of any further information to the United Kingdom. The British Government, under Clement Attlee, determined that a British Bomb was essential. Because of British involvement in the Manhattan Project, Britain had extensive knowledge in some areas, but not in others.

text: An improved version of 'Fat Man' was developed, and on 26 February 1952, Prime Minister Winston Churchill announced that the United Kingdom also had an atomic bomb and a successful test took place on 3 October 1952. At first these were free-fall bombs, intended for use by the V Force of jet bombers. A Vickers Valiant dropped the first UK nuclear weapon on 11 October 1956 at Maralinga, South Australia. Later came a missile, Blue Steel, intended for carriage by the V Force bombers, and then the Blue Streak medium-range ballistic missile (later canceled). Anglo-American cooperation on nuclear weapons was restored by the 1958 US-UK Mutual Defence Agreement. As a result of this and the Polaris Sales Agreement, the United Kingdom has bought United States designs for submarine missiles and fitted its own warheads. It retains full independent control over the use of the missiles. It no longer possesses any free-fall bombs.

text: France had been heavily involved in nuclear research before World War II through the work of the Joliot-Curies. This was discontinued after the war because of the instability of the Fourth Republic and lack of finances.[49] However, in the 1950s, France launched a civil nuclear research program, which produced plutonium as a byproduct.

text: In 1956, France formed a secret Committee for the Military Applications of Atomic Energy and a development program for delivery vehicles. With the return of Charles de Gaulle to the French presidency in 1958, final decisions to build a bomb were made, which led to a successful test in 1960. Since then, France has developed and maintained its own nuclear deterrent independent of NATO.

text: In 1951, China and the Soviet Union signed an agreement whereby China supplied uranium ore in exchange for technical assistance in producing nuclear weapons. In 1953, China established a research program under the guise of civilian nuclear energy. Throughout the 1950s the Soviet Union provided large amounts of equipment. But as the relations between the two countries worsened the Soviets reduced the amount of assistance and, in 1959, refused to donate a bomb for copying purposes. Despite this, the Chinese made rapid progress and tested an atomic bomb on October 16, 1964, at Lop Nur. They tested a nuclear missile on October 25, 1966, and a hydrogen bomb on June 14, 1967.

text: Chinese nuclear warheads were produced from 1968 and thermonuclear warheads from 1974.[50] It is also thought that Chinese warheads have been successfully miniaturised from 2200 kg to 700 kg through the use of designs obtained by espionage from the United States.[citation needed] The current number of warheads is unknown, but as of 2017 it is thought to be in the low hundreds.[51] China is the only nuclear weapons state to have guaranteed the non-first use of nuclear weapons.

text: Cold War[edit]

text: After World War II, the balance of power between the Eastern and Western blocs and the fear of global destruction prevented the further military use of atomic bombs. This fear was even a central part of Cold War strategy, referred to as the doctrine of Mutually Assured Destruction. So important was this balance to international political stability that a treaty, the Anti-Ballistic Missile Treaty (or ABM treaty), was signed by the U.S. and the USSR in 1972 to curtail the development of defenses against nuclear weapons and the ballistic missiles that carry them. This doctrine resulted in a large increase in the number of nuclear weapons, as each side sought to ensure it possessed the firepower to destroy the opposition in all possible scenarios.

text: Early delivery systems for nuclear devices were primarily bombers like the United States B-29 Superfortress and Convair B-36, and later the B-52 Stratofortress. Ballistic missile systems, based on Wernher von Braun's World War II designs (specifically the V-2 rocket), were developed by both United States and Soviet Union teams (in the case of the U.S., effort was directed by the German scientists and engineers although the Soviet Union also made extensive use of captured German scientists, engineers, and technical data).

text: These systems were used to launch satellites, such as Sputnik, and to propel the Space Race, but they were primarily developed to create Intercontinental Ballistic Missiles (ICBMs) that could deliver nuclear weapons anywhere on the globe. Development of these systems continued throughout the Cold War—though plans and treaties, beginning with the Strategic Arms Limitation Treaty (SALT I), restricted deployment of these systems until, after the fall of the Soviet Union, system development essentially halted, and many weapons were disabled and destroyed. On January 27, 1967, more than 60 nations signed the Outer Space Treaty, banning nuclear weapons in space.

text: There have been a number of potential nuclear disasters. Following air accidents U.S. nuclear weapons have been lost near Atlantic City, New Jersey (1957); Savannah, Georgia (1958) (see Tybee Bomb); Goldsboro, North Carolina (1961); off the coast of Okinawa (1965); in the sea near Palomares, Spain (1966) (see 1966 Palomares B-52 crash); and near Thule, Greenland (1968) (see 1968 Thule Air Base B-52 crash). Most of the lost weapons were recovered, the Spanish device after three months' effort by the DSV Alvin and DSV Aluminaut.

text: The Soviet Union was less forthcoming about such incidents, but the environmental group Greenpeace believes that there are around forty non-U.S. nuclear devices that have been lost and not recovered, compared to eleven lost by America, mostly in submarine disasters. The U.S. has tried to recover Soviet devices, notably in the 1974 Project Azorian using the specialist salvage vessel Hughes Glomar Explorer to raise a Soviet submarine. After news leaked out about this boondoggle, the CIA would coin a favorite phrase for refusing to disclose sensitive information, called glomarization: We can neither confirm nor deny the existence of the information requested but, hypothetically, if such data were to exist, the subject matter would be classified, and could not be disclosed.[52]

text: The collapse of the Soviet Union in 1991 essentially ended the Cold War. However, the end of the Cold War failed to end the threat of nuclear weapon use, although global fears of nuclear war reduced substantially. In a major move of symbolic de-escalation, Boris Yeltsin, on January 26, 1992, announced that Russia planned to stop targeting United States cities with nuclear weapons.

text: Cost[edit]

text: The designing, testing, producing, deploying, and defending against nuclear weapons is one of the largest expenditures for the nations which possess nuclear weapons. In the United States during the Cold War years, between "one quarter to one third of all military spending since World War II [was] devoted to nuclear weapons and their infrastructure." [53] According to a retrospective Brookings Institution study published in 1998 by the Nuclear Weapons Cost Study Committee (formed in 1993 by the W. Alton Jones Foundation), the total expenditures for U.S. nuclear weapons from 1940 to 1998 was $5.5 trillion in 1996 Dollars.[54]

text: For comparison, the total public debt at the end of fiscal year 1998 was $5,478,189,000,000 in 1998 Dollars[55] or $5.3 trillion in 1996 Dollars. The entire public debt in 1998 was therefore equal to the cost of research, development, and deployment of U.S. nuclear weapons and nuclear weapons-related programs during the Cold War.[53][54][56]

text: Second nuclear age[edit]

text: The second nuclear age can be regarded as proliferation of nuclear weapons among lesser powers and for reasons other than the American-Soviet-Chinese rivalry.

text: India embarked relatively early on a program aimed at nuclear weapons capability, but apparently accelerated this after the Sino-Indian War of 1962. India's first atomic-test explosion was in 1974 with Smiling Buddha, which it described as a "peaceful nuclear explosion."

text: After the collapse of Eastern Military High Command and the disintegration of Pakistan as a result of the 1971 Winter war, Bhutto of Pakistan launched scientific research on nuclear weapons. The Indian test caused Pakistan to spur its programme, and the ISI conducted successful espionage operations in the Netherlands, while also developing the programme indigenously. India tested fission and perhaps fusion devices in 1998, and Pakistan successfully tested fission devices that same year, raising concerns that they would use nuclear weapons on each other.

text: All of the former Soviet bloc countries with nuclear weapons (Belarus, Ukraine, and Kazakhstan) returned their warheads to Russia by 1996.

text: South Africa also had an active program to develop uranium-based nuclear weapons, but dismantled its nuclear weapon program in the 1990s.[57] Experts do not believe it actually tested such a weapon, though it later claimed it constructed several crude devices that it eventually dismantled. In the late 1970s American spy satellites detected a "brief, intense, double flash of light near the southern tip of Africa."[58] Known as the Vela Incident, it was speculated to have been a South African or possibly Israeli nuclear weapons test, though some feel that it may have been caused by natural events or a detector malfunction.

text: Israel is widely believed to possess an arsenal of up to several hundred nuclear warheads, but this has never been officially confirmed or denied (though the existence of their Dimona nuclear facility was confirmed by Mordechai Vanunu in 1986).

text: In January 2004, Dr A. Q. Khan of Pakistan's programme confessed to having been a key mover in "proliferation activities",[59] seen as part of an international proliferation network of materials, knowledge, and machines from Pakistan to Libya, Iran, and North Korea.

text: North Korea announced in 2003 that it had several nuclear explosives. The first claimed detonation was the 2006 North Korean nuclear test, conducted on October 9, 2006. On May 25, 2009, North Korea continued nuclear testing, violating United Nations Security Council Resolution 1718. A third test was conducted on 13 February 2013, two tests were conducted in 2016 in January and September, followed by test a year later in September 2017.