The Cold war was dominated almost half a century of global history. The Cold war rivalry was between the United States and the Soviet Union from 1945 to 1990 and resulted in mutual suspicions, heightened tensions and a series of international incidents that brought the world's super powers to the brink of disaster. The economical cause of Cold War was when the United States wanted to encourage free trade throughout the world whereas the Soviet Union wanted to shield off her own sphere from international commerce. These differences led to much ill feeling between the United States and the Soviet Union. For political cause, there was two system of government abide by these two nation's which is their ideologies, the difference in beliefs, one believe in communism (Russia) while the other in capitalism (USA). In the United States, the government is elected by free elections whereas in the Soviet Union, the government is formed by the Communist party so the people do not have the right or freedom to form their own political parties. With the decline of Europe, power was largely shared between the Soviet Union and the United States. Both wanted to dominate the other, conflicts were inevitable.