Franklin Roosevelt 's reputation as one of the great American presidents remains secure. In foreign affairs he was instrumental in moving the country from isolationism into a new era of international involvement and assertiveness that has endured since his death. During World War II he helped plan and direct the most successful military operation in the history of the nation. But while his presidency is the standard by which all his successors have been judged, it is also one of the most controversial . He provided the leadership and vision necessary to restore hope and to confront the greatest world crisis of the twentieth century, but his methods were often manipulative and deceptive. As an idealist with a coherent world vision, and a realist willing to make pragmatic deals, he was responsible for decisions and policies that were fundamentally important in the making of the world in which we live today.