The best way to look at all these interrelated questions is to compare the responses of the Wilson and Roosevelt administrations to the global conflicts that broke out during their time in office. Both Presidents hoped, at least initially, that the United States could stay out of the world wars and both undertook measures toward this end.

President Wilson was more vocal in advocating neutrality of public opinion as well as neutrality in foreign policy. Franklin Roosevelt was clear in his denunciation of the fascist regimes of Adolf Hitler and Benito Mussolini and portrayed the war that broke out in Europe in terms of good and evil. Wilson, despite his public comments, privately hoped, as did Roosevelt, to use the war to promote a democratic order around the world. Where Wilson insisted on the right to trade with belligerent nations—a stance that ultimately, more than any other factor, dragged the United States into war—Roosevelt was constrained by the Neutrality Acts passed by Congress that limited trade with nations at war. Initial German successes, however, nudged Congress toward Roosevelt's position through revisions to the acts that allowed first "cash and carry" and then "lend-lease" trade agreements with Great Britain and even the Soviet Union.

The United States entered each war late because of the circumstances of the war and because of domestic opposition to war. In both cases, the nation eventually went to war because of the threats and actions of belligerents. Wilson asked Congress for a declaration of war in response to Germany's policy of unrestricted submarine warfare, and Roosevelt led the nation into war after the Japanese attack on Pearl Harbor—an attack precipitated by FDR's resistance to Japanese expansion in the Pacific.

Both Presidents understood the transformative power of war and of the significance of American involvement. They sought to articulate their war aims through public statements. Wilson promulgated his "Fourteen Points" shortly after the United States declared war, and Roosevelt agreed to the Atlantic Charter with Winston Churchill not long before Pearl Harbor. In short, both Presidents attempted, with varying degrees of conviction, to keep the nation out of war but came to see the scale of the respective conflicts as opportunities to, as Wilson memorably said, "make the world safe for democracy" and to assert the nation's role as a global power.