Allies of World War II

thumb|"Long live the victory of the Anglo-Soviet-American military alliance!" – USSR stamp of 1943, quoting Stalin

The Allies, or Allied powers, formally referred to as the United Nations from 1942, were an international military coalition formed during World War II (1939–1945) to oppose the Axis powers. Its principal members were the "Big Four" — the United Kingdom, the Soviet Union, the United States, and China.

Membership in the Allies varied during the course of the war. When the conflict broke out on 1 September 1939, the Allied coalition consisted of the United Kingdom, France, and Poland, as well as their respective dependencies, such as British India. They were joined by the independent dominions of the British Commonwealth: Canada, Australia, New Zealand and South Africa. Consequently, the initial alliance resembled that of the First World War. As Axis forces began invading northern Europe and the Balkans, the Allies added the Netherlands, Belgium, Norway, Greece, and Yugoslavia. The Soviet Union, which initially had a non-aggression pact with Germany (which resulted in the Soviet invasion of Poland) joined the Allies after the German invasion of the Soviet Union in June 1941. The United States, while providing some material support to European Allies since September 1940, remained formally neutral until the Japanese attack on Pearl Harbor in December 1941, after which it declared war and officially joined the Allies. The Republic of China had already been at war with Japan since 1937 after the Marco Polo Bridge incident, and formally joined the Allies in December 1941.

The "Big Three"—the United Kingdom, the Soviet Union, and the United States—were the principal contributors of manpower, resources and strategy, each playing a key role in achieving victory. Relations between the United Kingdom and the United States were especially close, with their bilateral Atlantic Charter forming the basis of their alliance. A series of conferences between Allied leaders, diplomats, and military officials gradually shaped the makeup of the alliance, the direction of the war, and ultimately the postwar international order.

The Allies became a formalized group upon the Declaration by United Nations on 1 January 1942, which was signed by 26 countries around the world; these ranged from governments in exile from the Axis occupation to small states far removed from the war. The Declaration officially recognized the Big Three and China as the "Four Powers", acknowledging their central role in prosecuting the war; they were also referred to as the "trusteeship of the powerful", and later as the "Four Policemen" of the United Nations. Many more countries joined through to the final days of the war, including colonies and former Axis states. After the war ended, the Allies, and the Declaration that bound them, would become the basis of the modern United Nations.

Origins

Following the First World War, the Treaty of Versailles (1919) established the League of Nations in an attempt to create a system of collective security and prevent war. The League's covenant obliged members to protect the political and territorial integrity of all members against aggression. Four of the major allies of the First World Warthe United Kingdom, France, Italy and Japanbecame permanent members of the league's council. The league, however, was weakened by the failure of the United States to join and by the cumbersome rules for enforcing sanctions for breaches of its security provisions.

France attempted to further protect itself against possible future German attack with the Franco-Polish alliance (1921) and the Franco-Czechoslovak alliance (1924). Under the Locarno treaties (1925), France, Britain, Belgium, Germany and Italy also guaranteed the borders between Germany and France and Germany and Belgium as defined in the Treaty of Versailles.

Germany remilitarised the Rhineland in March 1936 in contravention of the Versailles and Locarno treaties but Britain, France and the League of Nations imposed no sanctions. Britain and France also began negotiations for a defence treaty with the Soviet Union but little progress was made. Two days later, Britain signed a military alliance with Poland.

Australia, New Zealand, South Africa and Canada declared war on Germany in the two weeks following the British declaration.

The First Inter-Allied Meeting took place in London in early June 1941 between the United Kingdom, the four allied British Dominions, the eight governments in exile, and Free France. The meeting culminated with the Declaration of St James's Palace, which committed the signatories to work together until victory was achieved and an enduring peace secured.

On 22 June 1941, Hitler broke the non-aggression agreement with Stalin and Axis forces invaded the Soviet Union.

The Big Three and Big Four

Winston Churchill called the association of the United Kingdom, United States, Soviet Union and other Allies the "Grand Alliance". The "Big Three"—the United Kingdom, United States and Soviet Union—were the principal contributors of manpower, resources and strategy, each playing a key role in achieving victory. The United States also saw China and its leader Chiang Kai-shek as its main ally in Asia and considered it one of the "Big Four" allied powers, a view not always shared by the United Kingdom and Soviet Union. The 26 original signatories were:

United States
United Kingdom
Soviet Union
China
Australia
Belgium
Canada
Costa Rica
Cuba
Czechoslovakia
Dominican Republic
El Salvador
Greece
Guatemala
Haiti
Honduras
British India
Luxembourg
Netherlands
New Zealand
Nicaragua
Norway
Panama
Poland
South Africa
Yugoslavia

From this time, countries that adopted the declaration were considered allies. Mexico, the Philippines and Ethiopia adopted the declaration later in 1942, followed by Iraq, Brazil, Bolivia, Iran and Colombia in 1943, and Liberia in February 1944. Following the liberation of France, the French provisional government signed the declaration on 26 December 1944 and France officially became one of the allied nations. Eleven nations adhered to the declaration in early 1945, when an allied victory over Germany was assured and the Big Four powers were preparing to invite signatories to the San Francisco Conference to prepare a charter for the new United Nations organization.

Major conferences

thumb|upright|Wartime poster for the [[Declaration by United Nations|United Nations, created in 1941 by the U.S. Office of War Information]]A series of conferences between the major allied leaders, diplomats, and military officials shaped the strategic direction of the war and the post-war international order. Churchill and Roosevelt attended the first Washington Conference (December 1941 – January 1942) where they established the Combined Chiefs of Staff Committee and agreed to prioritize the European and North African theatres in the war. Churchill and Roosevelt met again at Casablanca (January 1943) and Washington (May 1943) where they decided on an invasion of Sicily, the postponement of a landing in France until May 1944, and began planning a counter-offensive against Japan in Asia and the Pacific. At the first Quebec Conference (August 1943) Churchill and Roosevelt agreed to a new command structure in South-East Asia.

Churchill, Roosevelt and Chiang met at the Cairo Conference (November 1943) where they discussed operations against Japan and issued the Cairo Declaration outlining their vision for post-war Asia whereby Japan would lose all the territories it had gained since 1914. Stalin declined to attend or send representatives as the Soviet Union was not at war with Japan. Churchill, Roosevelt and Stalin met for the first time at the Tehran Conference (November – December 1943) where they decided that the full-scale offensive in France in mid-1944 was the allied priority and where Stalin announced that he would declare war on Japan once Hitler was defeated. At the Yalta Conference (February 1945) Churchill, Roosevelt and Stalin agreed to zones of occupation for the soon-to-be-defeated Germany and made plans for the post-war settlement of Europe and the United Nations organization. Following the allied victory in Europe, the new US president, Harry S. Truman, and new British prime minister, Clement Attlee, attended the final summit of the Big Three leaders at Potsdam (July – August 1945) where they discussed the final operations against Japan and issued a demand for its unconditional surrender. The British Commonwealth and empire obtained about half of the $42 to $50 billion in lend-lease aid during the war. The British Commonwealth and, to a lesser extent, the French empire and Soviet Union reciprocated with a smaller Reverse Lend-Lease program worth about $8 billion. After the United States entered the war, the United Kingdom and the United States established a Combined Chiefs of Staff to harmonize military planning, and Combined Boards to co-ordinate shipping, raw materials, and war production.

Churchill and Roosevelt also met nine times in conferences without the presence of the other Big Four leaders. At the First Washington Conference, held soon after the United States entered the war, they agreed that Germany should be first defeated before focusing their forces on Japan.

There were also significant disagreements between the United Kingdom and United States about the Asia-Pacific front. While Churchill prioritized the recovery of British imperial possessions such as Burma, Malaya, Hong Kong and Singapore, the Americans were more focused on supporting China by reopening its overland supply lines from India through the Burma road. The Soviet Union, in turn, prosecuted the bulk of the ground war in which an estimated 5 million Axis soldiers were killed or missing in action on the eastern front.

A rift developed between the Soviet Union and the western allies over the political settlement of postwar Europe. The Soviet Union pressed the United Kingdom and United States to recognise the territorial gains it had made in the Baltic states, Finland, Bessarabia and eastern Poland before the German invasion. The United Kingdom and United States rejected these demands as incompatible with the Atlantic Charter principle of no territorial changes without the consent of the people concerned. Chiang's standing with the other allied leaders was weakened by the poor performance of his army during this offensive and by the US adoption of the island hopping strategy against Japan which reduced the importance of bases in China. Chiang was not invited to the Yalta and Potsdam conferences of 1945.

Major Allied states

United Kingdom and British Empire

At the outbreak of the war, the British Empire comprised over 60 countries including the dominions, India, Burma, and numerous Crown colonies and protectorates. Following Britain's declaration of war on Germany on 3 September 1939, most of the empire was automatically at war. However, the dominions of Australia, Canada, New Zealand and South Africa separately declared war in the following two weeks.

Following the defeat of Poland in October 1939 and of France in June 1940, the UK took the lead in coordinating the war effort of its empire and the allied governments-in-exile in London. When the Soviet Union joined the Allies after the Axis invasion of June 1941 and the United States and China joined in December that year, the UK was the de facto representative of the empire and allied governments-in-exile in their dealings with the other Big Four powers.

Britain sustained its war effort by drawing on the population, raw material and strategic bases of its colonies throughout the world. In 1939, the population of the empire, including the dominions, was about 484 million, making it the second most populous belligerent after China. Britain’s colonies accounted for 42% of the empire’s economic output. After Japan occupied most of Britain's Asia-Pacific colonies including Hong Kong, Burma, Malaya and Singapore from December 1941, Britain expanded the production of food and manufacturing in India and the African colonies.

Britain’s colonies also made a significant contribution to the allied military effort. By 1945, 25% of the allied South-East Asia Command was African and about 4% of the empire's military dead were from the colonies other than India.

In 1939 Britain had the second largest navy and largest merchant navy in the world, and these played a vital role in transporting troops, armaments, food and raw materials for the Allies. The British military played a major role in defeating the Axis powers in North Africa, Italy and the Western Front British and colonial troops also cleared Japanese forces from Burma. Britain and the United States conducted the Combined Bomber Offensive against Germany from 1943 which diverted German resources from the Eastern Front and retarded German war production.<gallery mode=packed heights=180>

File:Spitfire and He 111 during Battle of Britain 1940.jpg|British Supermarine Spitfire fighter aircraft (bottom) flying past a German Heinkel He 111 bomber aircraft (top) during the Battle of Britain in 1940

File:IWM-E-6724-Crusader-19411126.jpg|British Crusader tanks during the North African Campaign

File:HMS Ark Royal attack.jpg|British aircraft carrier under attack from Italian aircraft during the Battle of Cape Spartivento (27 November 1940)

File:The British Army in North-west Europe 1944-45 B15008.jpg|British soldiers of the King's Own Yorkshire Light Infantry in Elst, Netherlands on 2 March 1945

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India

About two-thirds of India was under the direct rule of the United Kingdom exercised by a viceroy representing the British crown. The other third mostly consisted of princely states, nominally under Indian rulers subordinate to the British crown. Nevertheless, India separately signed the Declaration by United Nations on 2 January 1942, and signed the Paris Peace Treaties of February 1947 as an Allied Power.

India was an important supply base for Commonwealth, American and Chinese forces and itself produced about £286.5 million worth of military equipment and other supplies. By 1945, the Indian army numbered 2.5 million people the largest volunteer army in history. Indian troops played a major role in the Burma campaign and in other theaters. Its military losses were about 100,000 killed, wounded or missing, and almost 80,000 taken prisoner. An estimated 3 million Indian people died in the Bengal famine of 1943.

France

thumb|[[Free French forces at the Battle of Bir Hakeim, 1942]]

War declared

thumb|FAFL Free French GC II/5 "LaFayette" receiving ex-USAAF [[Curtiss P-40 fighters at Casablanca, French Morocco]]

thumb|[[Scuttling of the French fleet in Toulon|The French fleet scuttled itself rather than fall into the hands of the Axis after their invasion of Vichy France on 11 November 1942.]]

After Germany invaded Poland, France declared war on Germany on 3 September 1939. In January 1940, French Prime Minister Édouard Daladier made a major speech denouncing the actions of Germany: