The task of rebuilding Europe and Asia after World War II led to an increase in the existing rivalry between the United States and the Soviet Union. Neither country wanted the other to extend its sphere of influence; each tried to do what it could to undermine the other's power.
For example, under the European Recovery Program, also known as the Marshall Plan, the United States helped countries in Western Europe through financial aid worth $17 billion. The plan was in effect for four years. One of the objectives of the Marshall Plan was to prevent communism from gaining traction in countries still in the process of recovering from the effects of the war. Soviet Russia did not participate in the plan and prevented countries such as Poland from participating in the plan.
The Yalta Conference of 1945 was another event that exacerbated existing tensions between the United States and the Soviet Union. The participants agreed that all pre-war governments would be restored to facilitate redevelopment; however, the Soviets set up puppet governments in Hungary, Bulgaria, and Poland. The rapid increase in the Soviet sphere of political influence deepened mutual mistrust, and in a few years the world entered the era of Cold War.
In China, the communists rose to power with Russia's help. After this, the Americans became more influential with the Japanese. Many parts of Asia saw a redrawing of borders during the rebuilding process; Pakistan was created, as was the state of Israel. Incompatibility between Islamic and communist philosophy drew Muslim nations of the Middle East toward the American sphere of influence.