Truman DoctrineThis pronouncement and its uses expanded the nation’s role in checking the spread of communism in the postwar era. In the early months of the cold war, as the atmosphere of wartime cooperation disintegrated, the British were propping up the Greek government against communist guerrillas believed to be receiving support from Moscow. In February 1947, facing financial problems and the end of its empire, Great Britain announced its plans to withdraw, prompting American fears that Greece and perhaps Turkey would fall under Soviet control.ater the same year.