At the end of World War II, there was a war between two groups of nations. The Soviet Union and the Axis powers. The Soviet Union was mainly consisted of the United States,Britain,France,and Russia,which was made up of democratic republic system. Then the Axis power consisted Germany,Italy,and Japan,which was based on a dictatorship. In 1941,the Soviet Union was being invaded by the Axis powers,and United States was reinforced in the aftermath of the Japanese attack on Pearl Harbor. Under the Lend-Lease Act, the United States consigned enormous quantities of war materiel to the Soviet Union, which was critical in helping the Soviets defeat the Nazi invasion.