sentences:  However, American leaders were reluctant to renounce unilateral interventionism until the Good Neighbor policy enunciated by President Franklin Roosevelt in 1933.The era of the Good Neighbor Policy ended with the ramp-up of the Cold War in 1945, as the United States felt there was a greater need to protect the western hemisphere from Soviet influence.These changes conflicted with the Good Neighbor Policy's fundamental principle of non-intervention and led to a new wave of US involvement in Latin American affairs.