The Second World War broke out twenty-one years after the conclusion of the First World War. Allies from World War I teamed up with the Axis Powers in World War II to fight the reconstituted Central Powers, dubbed the Axis Powers.
A new ally for Britain and France was Poland, which had just gained its independence as a sovereign nation after World War I. Canada, Australia, and South Africa, all former colonies of the British Empire, joined the Allies soon after.
During WWII, as the number of nations engaged grew, more than 20 Allies would join the fight, including those without a military.
World War II’s Big Three Allies and the Four Great Powers
With their immense influence, three of the most important Allied allies came on board late yet made a huge difference. The first was Russia, which had signed a non-aggression treaty with Germany and therefore started WWII as one of the Axis Powers.
When Germany first invaded Poland in 1939, Russia aided them. However, in 1941, Germany breached the non-aggression treaty by attacking Russia, which prompted Russia to transfer allegiances to the Allies.
The United States, as in the first World War, tried to isolate itself from Europe and join the list of nations that stayed neutral in WWII during the early stages of the conflict.
Everything changed when the Japanese destroyed Pearl Harbor, Hawaii, in December 1941. As a result, the United States officially joined the war, sending troops to the European and Pacific fronts in large numbers.
Even though it had been at war with the Axis since 1937, China joined the Allies in December 1941, a significant event. With China, the Four Powers were formed: the United Kingdom, Russia, the United States, and the Soviet Union.
With three of the world’s biggest armed forces and some of its greatest nuclear arsenals, they were still military superpowers in 2019. United Nations was established after WWII, with 193 nations and two observer governments participating in its activities.
Allies in World War II include:
Country | Date Joined | Country | Date Joined | Country | Date Joined | ||
---|---|---|---|---|---|---|---|
Argentina | 27 March 1945 | Finland* | 15 Sept. 1944 | Oman | 10 Sept. 1939 | ||
Australia | 3 Sept. 1939 | France | 3 Sept. 1939 | Panama | 7 Dec. 1941 | ||
Belgium | 10 May 1940 | Greece | 28 Oct 1940 | Paraguay | 7 Feb. 1945 | ||
Bolivia | 7 Apr. 1943 | Guatemala | 9 Dec. 1941 | Peru | 12 Feb. 1945 | ||
Brazil | 22 Aug. 1942 | Haiti | 8 Dec 1941 | Philippines | 8 Dec 1941 | ||
British India | 3 Sept. 1939 | Honduras | 8 Dec. 1941 | Poland | 1 Sept. 1939 | ||
Bulgaria* | 8 Sept. 1944 | Iran | 9 Sept. 1943 | Romania* | 25 Aug. 1944 | ||
Canada | 10 Sept. 1939 | Iraq | 16 Jan. 1943 | Saudi Arabia | 1 Mar. 1945 | ||
Chile | 11 April 1945 | Lebanon | 27 Feb. 1945 | South Africa | 6 Sept. 1939 | ||
China | 9 Dec 1941 | Italy* | 10 Oct. 1943 | South Korea* | 10 Dec. 1941 | ||
Colombia | 26 July 1943 | Liberia | 27 Jan. 1944 | Soviet Union | 22 June 1941 | ||
Costa Rica | 8 Dec. 1941 | Luxembourg | 10 May 1940 | Syria | 26 Feb. 1945 | ||
Cuba | 9 Dec. 1941 | Mexico | 22 May 1942 | Turkey | 23 Feb. 1945 | ||
Czechoslovakia* | 16 Dec. 1941 | Mongolia | 1 Aug 1945 | United Kingdom | 3 Sept. 1939 | ||
Denmark | 8 Apr. 1940 | Nepal | 4 Sept. 1939 | United States | 8 Dec. 1941 | ||
Dominican Rep. | 8 Dec. 1941 | Netherlands | 10 May 1940 | Uruguay | 15 Feb. 1945 | ||
Ecuador | 2 Feb. 1945 | New Zealand | 3 Sept. 1939 | Venezuela | 15 Feb. 1945 | ||
Egypt | 24 Feb. 1945 | Nicaragua | 8 Dec. 1941 | Vietnam (Viet Minh) | 7 Dec. 1941 | ||
El Salvador | 8 Dec. 1941 | Norway | 8 Apr. 1940 | Yugoslavia | 6 Apr. 1941 | ||
Ethiopia | 14 Dec. 1942 |
A few things to keep in mind:
Also See: Allies During WWI 2022
- When the war started, Bulgaria was an Axis power.
- The genuine government of Czechoslovakia declared its support to the occupying powers while exiled from the nation.
- As part of the Continuation War, Finland fought with Germany and Russia and did not declare war on Germany until March 3, 1945. Although it was retroactive to September 15, 1944, the proclamation was still effective.
- Italy and Romania were Axis states at the start of World War II.
- South Korea’s leadership declared provisional administration at the time.
- The revolutionary government of the Viet Minh announced Vietnam’s loyalty.
Country | 2022 Population |
---|---|
China | 1448471.4000 |
India | 1406631.7760 |
United States | 334805.2690 |
Indonesia | 279134.5050 |
Pakistan | 229488.9940 |
Nigeria | 216746.9340 |
Brazil | 215353.5930 |
Bangladesh | 167885.6890 |
Russia | 145805.9470 |
Mexico | 131562.7720 |
Japan | 125584.8380 |
Ethiopia | 120812.6980 |
Philippines | 112508.9940 |
Egypt | 106156.6920 |
Vietnam | 98953.5410 |
DR Congo | 95240.7920 |
Iran | 86022.8370 |
Turkey | 85561.9760 |
Germany | 83883.5960 |
Thailand | 70078.2030 |
United Kingdom | 68497.9070 |
France | 65584.5180 |
Tanzania | 63298.5500 |
South Africa | 60756.1350 |
Italy | 60262.7700 |
Kenya | 56215.2210 |
Myanmar | 55227.1430 |
Colombia | 51512.7620 |
South Korea | 51329.8990 |
Uganda | 48432.8630 |
Spain | 46719.1420 |
Argentina | 46010.2340 |
Sudan | 45992.0200 |
Algeria | 45350.1480 |
Ukraine | 43192.1220 |
Iraq | 42164.9650 |
Afghanistan | 40754.3880 |
Canada | 38388.4190 |
Morocco | 37772.7560 |
Poland | 37739.7850 |
Saudi Arabia | 35844.9090 |
Angola | 35027.3430 |
Uzbekistan | 34382.0840 |
Peru | 33684.2080 |
Malaysia | 33181.0720 |
Mozambique | 33089.4610 |
Ghana | 32395.4500 |
Yemen | 31154.8670 |
Nepal | 30225.5820 |
Venezuela | 29266.9910 |
Madagascar | 29178.0770 |
Cameroon | 27911.5480 |
Ivory Coast | 27742.2980 |
Niger | 26083.6600 |
Australia | 26068.7920 |
North Korea | 25990.6790 |
Taiwan | 23888.5950 |
Burkina Faso | 22102.8380 |
Sri Lanka | 21575.8420 |
Mali | 21473.7640 |
Malawi | 20180.8390 |
Zambia | 19470.2340 |
Syria | 19364.8090 |
Chile | 19250.1950 |
Kazakhstan | 19205.0430 |
Romania | 19031.3350 |
Guatemala | 18584.0390 |
Ecuador | 18113.3610 |
Senegal | 17653.6710 |
Chad | 17413.5800 |
Netherlands | 17211.4470 |
Cambodia | 17168.6390 |
Somalia | 16841.7950 |
Zimbabwe | 15331.4280 |
Guinea | 13865.6910 |
Rwanda | 13600.4640 |
Benin | 12784.7260 |
Burundi | 12624.8400 |
Tunisia | 12046.6560 |
Bolivia | 11992.6560 |
Haiti | 11680.2830 |
Belgium | 11668.2780 |
South Sudan | 11618.5110 |
Cuba | 11305.6520 |
Dominican Republic | 11056.3700 |
Czech Republic | 10736.7840 |
Greece | 10316.6370 |
Jordan | 10300.8690 |
Azerbaijan | 10300.2050 |
Honduras | 10221.2470 |
Sweden | 10218.9710 |
Portugal | 10140.5700 |
United Arab Emirates | 10081.7850 |
Tajikistan | 9957.4640 |
Hungary | 9606.2590 |
Belarus | 9432.8000 |
Papua New Guinea | 9292.1690 |
Austria | 9066.7100 |
Israel | 8922.8920 |
Switzerland | 8773.6370 |
Togo | 8680.8370 |
Serbia | 8653.0160 |
Sierra Leone | 8306.4360 |
Hong Kong | 7604.2990 |
Laos | 7481.0230 |
Paraguay | 7305.8430 |
Libya | 7040.7450 |
Bulgaria | 6844.5970 |
Nicaragua | 6779.1000 |
Kyrgyzstan | 6728.2710 |
Lebanon | 6684.8490 |
El Salvador | 6550.3890 |
Turkmenistan | 6201.9430 |
Singapore | 5943.5460 |
Denmark | 5834.9500 |
Republic of the Congo | 5797.8050 |
Finland | 5554.9600 |
Norway | 5511.3700 |
Slovakia | 5460.1930 |
Palestine | 5345.5410 |
Oman | 5323.9930 |
Liberia | 5305.1170 |
Costa Rica | 5182.3540 |
Ireland | 5020.1990 |
Central African Republic | 5016.6780 |
Mauritania | 4901.9810 |
New Zealand | 4898.2030 |
Panama | 4446.9640 |
Kuwait | 4380.3260 |
Croatia | 4059.2860 |
Moldova | 4013.1710 |
Georgia | 3968.7380 |
Eritrea | 3662.2440 |
Uruguay | 3496.0160 |
Mongolia | 3378.0780 |
Bosnia and Herzegovina | 3249.3170 |
Jamaica | 2985.0940 |
Qatar | 2979.9150 |
Armenia | 2971.9660 |
Albania | 2866.3740 |
Puerto Rico | 2829.8120 |
Lithuania | 2661.7080 |
Namibia | 2633.8740 |
Gambia | 2558.4820 |
Botswana | 2441.1620 |
Gabon | 2331.5330 |
Lesotho | 2175.6990 |
North Macedonia | 2081.3040 |
Slovenia | 2078.0340 |
Guinea-Bissau | 2063.3670 |
Latvia | 1848.8370 |
Bahrain | 1783.9830 |
Equatorial Guinea | 1496.6620 |
Trinidad and Tobago | 1406.5850 |
Timor-Leste | 1369.4290 |
Estonia | 1321.9100 |
Mauritius | 1274.7270 |
Cyprus | 1223.3870 |
Eswatini | 1184.8170 |
Djibouti | 1016.0970 |
Fiji | 909.4660 |
Reunion | 908.0610 |
Comoros | 907.4190 |
Guyana | 794.0450 |
Bhutan | 787.9410 |
Solomon Islands | 721.1590 |
Macau | 667.4900 |
Luxembourg | 642.3710 |
Montenegro | 627.9500 |
Western Sahara | 626.1610 |
Suriname | 596.8310 |
Cape Verde | 567.6780 |
Maldives | 540.9850 |
Brunei | 445.4310 |
Malta | 444.0330 |
Belize | 412.1900 |
Bahamas | 400.5160 |
Guadeloupe | 399.7940 |
Martinique | 374.0870 |
Iceland | 345.3930 |
Vanuatu | 321.8320 |
French Guiana | 314.1690 |
New Caledonia | 290.9150 |
Barbados | 288.0230 |
Mayotte | 286.2590 |
French Polynesia | 284.1640 |
Sao Tome and Principe | 227.6790 |
Samoa | 202.2390 |
Saint Lucia | 185.1130 |
Guam | 171.5190 |
Curacao | 165.5290 |
Kiribati | 123.4190 |
Micronesia | 117.4890 |
Grenada | 113.4750 |
Saint Vincent and the Grenadines | 111.5510 |
Tonga | 107.7490 |
Aruba | 107.6090 |
United States Virgin Islands | 103.9710 |
Antigua and Barbuda | 99.5090 |
Seychelles | 99.4260 |
Isle of Man | 85.7320 |
Andorra | 77.4630 |
Dominica | 72.3440 |
Cayman Islands | 67.2770 |
Bermuda | 61.9390 |
Marshall Islands | 60.0570 |
Northern Mariana Islands | 58.2690 |
Greenland | 56.9730 |
American Samoa | 55.0300 |
Saint Kitts and Nevis | 53.8710 |
Faroe Islands | 49.2330 |
Sint Maarten | 43.9660 |
Monaco | 39.7830 |
Turks and Caicos Islands | 39.7410 |
Saint Martin | 39.7300 |
Liechtenstein | 38.3870 |
San Marino | 34.0850 |
Gibraltar | 33.7040 |
British Virgin Islands | 30.5960 |
Palau | 18.2330 |
Cook Islands | 17.5710 |
Anguilla | 15.2300 |
Tuvalu | 12.0660 |
Wallis and Futuna | 10.9820 |
Nauru | 10.9030 |
Saint Barthelemy | 9.9450 |
Saint Pierre and Miquelon | 5.7590 |
Montserrat | 4.9650 |
Falkland Islands | 3.5390 |
Niue | 1.6220 |
Tokelau | 1.3780 |
Vatican City | 0.7990 |