In 1945, Harry S Truman became president of the USA, determined to confront Communism. He is reported to have told his advisers:

The Russians only understand one language - how many armies have you got? I'm tired of babying the Soviets.Harry S Truman, 1945

This was not the only cause of trouble. Historians believed that the wartime alliance between the Soviet Union and America was also wrecked by the huge differences between the two countries in:

  • politics - America was capitalist, Russia was communist
  • lifestyle - America had freedom and a two-party democracy - Russia had secret police and a one-party state
  • aims - America wanted Germany to recover as a trading partner - Russia wanted to weaken Germany and create a buffer zone of friendly states around Russia

The collapse of the wartime alliance led to a Cold War between the two superpowers.