Elected in the midst of the Great Depression, Roosevelt transformed the Presidency. Roosevelt's leadership during the Second World War gave the presidential role of Commander-in-Chief a new meaning. Henceforth, the President would be responsible not only for American foreign and defence policy, but would also play a leading role in helping to achieve collective security against aggression. But, did Roosevelt create an impossible Presidency, an office whose responsibilities were so great that no one could ever fulfil them satisfactorily?