The large increase in the number of separate countries in the world since World War II has been influenced most seriously by:?

Following World War II, rapid decolonization swept across the continent of Africa as many territories gained their independence from European colonization. In August 1941, United States President Franklin D. Roosevelt and British Prime Minister Winston Churchill met to discuss their post-war goals. In that meeting, they agreed to the Atlantic Charter, which in part stipulated that they would, "respect the right of all peoples to choose the form of government under which they will live; and they wish to see sovereign rights and self government restored to those who have been forcibly deprived of them." This agreement became the post-WWII stepping stone toward independence as nationalism grew throughout Africa.