Cold war.

At World War II's end in 1945, the U.S.S.R. (Soviet Union) led by Josef Stalin was increasing his attempt to spread communism to surrounding countries. Meanwhile the United States, a country who had been anally in the war, was now taking part in efforts to contain the Stalin and the Soviets from spreading communism to the rest of Europe and Asia. The Soviets had built an Iron Curtain down the middle of Germany …

…for nearly three-quarters the cost. President Truman helped most of the world overcome difficulties by giving them money and aid. Fronts were put up around the U.S.S.R. in order to contain the power that had once been an ally. America's involvement in the containment of Stalin and the Soviet Union's spread of communism, proved to be vital in the effort to keep the most of the world form being overturned by communism.