The impact of World War Two can be considered in two ways: during and after the war.
In the 1930s–1940s, while Liberia remained independent and Germany retained Togoland, the rest of West Africa was primarily under British and French control. West Africa had essential strategic importance for maritime and aerial operations. Freetown, in British Sierra Leone, was a crucial naval base—especially after the Allies, with the combined forces of the Anglo-French fleet, failed to take Dakar, Senegal (Sorley 2004).
After the fall of France in 1940, Northern Africa was under Vichy control. Charles De Gaulle’s government seized a larger swath of western and central Africa, including Cameroon and French Equatorial Africa. De Gaulle himself traveled to Cameroon to oversee operations. The Free French African territory extended from the Sahara south to the Equator and eastward through Chad (see Jennings 2015).
In addition to examining how the war was conducted in West Africa, one should address the contributions of West African people to the war effort. Beginning in 1939, the colonial rulers sent African soldiers to all the combat theaters. For example, about 40,000 French African soldiers fought against the German invasion in the 1940 Battle for France. Many laid down their lives, and others became prisoners of war. Their service alongside white European soldiers demonstrated the equality that colonization had long denied them.
The post-war impact lies mainly in the catalyst the war provided toward independence. While the results were not immediate, the liberation movements gained strength from the mid-1940s on. The 1945 Fifth Pan African Congress promoted the cause. The Atlantic Charter that Britain and the United States signed stated the Allies' support for all peoples’ rights to choose their form of government. With the formation of the United Nations, the republics that formed gained a larger voice in global, as well as African, affairs.
Davidson, Basil. 2015. Modern Africa: A Social and Political History. 3rd ed. London and New York: Routledge. https://books.google.com/books?id=VYwABAAAQBAJ&source=gbs_book_other_versions
Babou, Cheikh. 2010. “Decolonization or National Liberation: Debating the End of British Colonial Rule in Africa.” Annals of the American Academy of Political and Social Science 632: 41-54. http://www.jstor.org/stable/27895947
Jennings, Eric. 2015. Free French Africa in World War II: The African Resistance. Cambridge: Cambridge University Press. https://www.cambridge.org/us/academic/subjects/history/twentieth-century-regional-history/free-french-africa-world-war-ii-african-resistance?format=PB&isbn=9781107696976
Sorley, Graham. 2004. HMS Barham at Dakar. WorldWar2Peoples War. British Broadcasting Company. https://www.bbc.co.uk/history/ww2peopleswar/stories/45/a2231245.shtml