The Second World War did not fundamentally alter the political relationship between the European powers and their African colonies during the conflict itself, but it prompted reforms that later appeared to lead toward independence. Britain and France developed programmes of social and economic reform intended to give empire a new image, while also responding to American criticism and the altered balance of international power. These initiatives marked a turning point in colonial rule, even where their roots lay in pre-war discussions.

British policy moved away from the earlier doctrine that individual colonies should be economically self-supporting. The Colonial Development and Welfare Act of 1940 provided up to £5 million annually, and the 1945 Act set aside £120 million for post-war development and welfare over ten years. In French Africa, the FIDES programme was introduced at Brazzaville, presenting colonial policy as the development of overseas territories and the improvement of African living standards. Belgium likewise launched an ambitious development programme in the Congo with a strong welfare component, while making no immediate political concessions.

The war also strengthened international scrutiny of colonial rule. Proposals for international supervision of colonial dependencies were resisted by Churchill and de Gaulle, but the United Nations later replaced the League of Nations mandate system with trusteeship arrangements that permitted visiting missions and petitions from inhabitants. Administering powers acquired an explicit obligation to promote the progressive development of trust territories toward independence, although South Africa refused to accept these innovations for its South West African mandate.

African political elites initially often expressed loyalty to the Allied powers while hoping for accelerated constitutional reform. Habib Bourguiba, imprisoned by the French in 1938, appealed in May 1943 to Tunisians to support France against Nazi Germany. Elsewhere, demands for responsible government and independence remained less clearly defined, but wartime reforms soon appeared inadequate. Colonial governments were pushed either toward further concessions or repression, and repression frequently strengthened nationalist determination.

The war broadened the social and economic conditions available to African nationalists. It exposed political activists to influences that had been largely excluded from the colonial world of the 1930s, created new opportunities for mobilisation, and encouraged more urgent demands for social reform and constitutional advance. The conflict therefore helped mature African nationalism, even though the immediate wartime political response of many colonial elites remained cautious or loyalist.

African soldiers and military labourers played a substantial role in the Allied war effort. As many as 80,000 French African soldiers were fighting on the European front when France fell, while troops from French Equatorial Africa, French West Africa, and Madagascar later served in North Africa and the Middle East. Britain recruited throughout its African colonies, including Tanganyika, for the East African campaign, and African troops were also sent to India for the Burma campaign. Around one million African troops and carriers, including non-white non-combatants from South Africa, were used during the war.