British Empire in World War II
When the United Kingdom declared war on Nazi Germany in September 1939 at the start of World War II, it controlled to varying degrees numerous crown colonies, protectorates, and India. It also maintained unique political ties to four of the five independent Dominions—Australia, Canada, South Africa, and New Zealand[note 1]—as co-members (with the UK) of the then "British Commonwealth".[1] In 1939 the British Empire and the Commonwealth together comprised a global power, with direct or de facto political and economic control of 25% of the world's population, and of 30% of its land mass.[2]
See also: Military history of the United Kingdom during World War II and Diplomatic history of World War II
The contribution of the British Empire and Commonwealth in terms of manpower and materiel was critical to the Allied war-effort. From September 1939 to mid-1942, the UK led Allied efforts in multiple global military theatres. Commonwealth, Colonial and Imperial Indian forces, totalling close to 15 million serving men and women, fought the German, Italian, Japanese and other Axis armies, air-forces and navies across Europe, Africa, Asia, and in the Mediterranean Sea and the Atlantic, Indian, Pacific and Arctic Oceans. Commonwealth forces based in Britain operated across Northwestern Europe in the effort to slow or stop Axis advances. Commonwealth airforces fought the Luftwaffe to a standstill over Britain, and Commonwealth armies defeated Italian forces in East Africa and North Africa and occupied several overseas colonies of German-occupied European nations. Following successful engagements against Axis forces, Commonwealth troops invaded and occupied Libya, Italian Somaliland, Eritrea, Ethiopia, Iran, Iraq, Syria, Lebanon, Iceland, the Faroe Islands, and Madagascar.[3]
The Commonwealth defeated, held back or slowed the Axis powers for three years while mobilizing its globally-integrated economy, military, and industrial infrastructure to build what became, by 1942, the most extensive military apparatus of the war. These efforts came at the cost of 150,000 military deaths, 400,000 wounded, 100,000 prisoners, over 300,000 civilian deaths, and the loss of 70 major warships, 39 submarines, 3,500 aircraft, 1,100 tanks and 65,000 vehicles. During this period the Commonwealth built an enormous military and industrial capacity. Britain became the nucleus of the Allied war-effort in Western Europe, and hosted governments-in-exile in London to rally support in occupied Europe for the Allied cause. Canada delivered almost $4 billion in direct financial aid to the United Kingdom, and Australia and New Zealand began shifting to domestic production to provide material aid to US forces in the Pacific. Following the US entry into the war in December 1941, the Commonwealth and the United States coordinated their military efforts and resources globally. As the scale of the US military involvement and industrial production increased, the US undertook command in many theatres, relieving Commonwealth forces for duty elsewhere, and expanding the scope and intensity of Allied military efforts.[4][5] Co-operation with the Soviet Union also developed. However, it proved difficult to co-ordinate the defence of far-flung colonies and Commonwealth countries from simultaneous attacks by the Axis powers. In part this difficulty was exacerbated by disagreements over priorities and objectives, as well as over the deployment and control of joint forces.
Although the British Empire emerged from the war as one of the primary victors, regaining all colonial territories that had been lost during the conflict, it had become financially, militarily and logistically exhausted. The British Empire's position as a global superpower was supplanted by the United States, and Britain hitherto no longer played as great of a role in international politics as it had previously done so. Stoked by the war, rising nationalist sentiments in British colonies, in particular those in Africa and Asia, led to the gradual dissolution of the British Empire during the second half of the 20th century through decolonisation.[6][7]
Pre-war plans for defence[edit]
From 1923, defence of British colonies and protectorates in East Asia and Southeast Asia was centred on the "Singapore strategy". This made the assumption that Britain could send a fleet to its naval base in Singapore within two or three days of a Japanese attack, while relying on France to provide assistance in Asia via its colony in Indochina and, in the event of war with Italy, to help defend British territories in the Mediterranean.[8] Pre-war planners did not anticipate the fall of France: Nazi occupation, the loss of control over the Channel, and the employment of French Atlantic ports as forward bases for U-boats directly threatened Britain itself, forcing a significant reassessment of naval defence priorities.
During the 1930s, a triple threat emerged for the British Commonwealth in the form of militaristic governments in Germany, Italy, and Japan.[9] Germany threatened Britain itself, while Italy and Japan's imperial ambitions looked set to clash with the British imperial presence in the Mediterranean and East Asia respectively. However, there were differences of opinion within the UK and the Dominions as to which posed the most serious threat, and whether any attack would come from more than one power at the same time.
