Before World War I, Africa and the Middle East were divided up among European empires. Following the collapse of these empires after World War II, a wave of independence movements in Africa and the Middle East brought new nations into existence. The colonial era had left some areas richer and more developed than others. Colonial governments had divided people along racial, religious, and ethnic lines. In the postcolonial era, the former empires—and the new superpowers, the United States and the Soviet Union—had business and military interests in Africa and the Middle East that caused them to interfere with the newly free nations.