Robert E. Hannigan's book rethinks the role of the United States during and after World War I. Hannigan starts from the position that the history of the diplomacy of the war has been led by European historians who do not attempt to make a serious study of American policy. On the other hand, he argues, American historians have tended to ignore the European context of the war and to take Wilson's carefully crafted “idealistic” statements too literally. Developing the thesis of his earlier book, The New World Power: American Foreign Policy, 1898–1917 (2002), Hannigan suggests that despite his idealistic rhetoric, Wilson realistically pursued the conservative policy of the Monroe Doctrine and the open door in Latin American and Asian affairs. These policies were expected to prevent great-power colonialism that would obstruct access to resources and markets in the undeveloped parts of the world. Like his predecessors, Wilson wanted stability and a maintenance of the status quo, as his intervention in Mexico and the Caribbean revealed.

The outbreak of war in 1914 and the possibility of a German victory threatened to bring about a new world order that was more nationalistic and protectionist than the “Pax Britannica” commercial world of the nineteenth century with which the United States, and Wilson, felt quite comfortable. Wilson wanted to keep the United States out of the war, but saw a German victory as threatening this stability. He also saw himself positioned to broker a peace; not to create a new world order, Hannigan posits, but to insure that the contours of Pax Britannica were secured. Germany's submarine challenge forced Wilson to take the country into the war, albeit at a sacrifice of civil liberties. But Wilson still sought to bring about a peace settlement, which would reestablish the predominance of the Western great powers, essentially British predominance, while retaining in Germany a sufficient balance (“peace without victory”). In short, Wilson wanted something of a return to a status quo ante bellum in Western Europe and safe and stable new regimes for the most volatile parts of Eastern Europe – for example, Poland, Czechoslovakia, Hungary, and what became Yugoslavia – but not “self-determination” across the world. The Versailles Treaty was intended to create this stable Europe, and the League of Nations was to maintain the Western great-power status quo, Hannigan says.

This argument certainly makes understandable the many clashes Wilson had with his colleagues in Paris and with the United States Senate, as well as with disappointed minorities around the world. By 1918 and 1919 the Allies, and particularly the French, wanted a peace that rendered Germany incapable of overturning the Western European establishment. The United States Senate, while perhaps willing to accept a version of the status quo ante bellum, insisted on maintaining the power to make its own decisions about United States responsibilities in other parts of the world, which Article X of the League of Nations Covenant appeared to overrule. Finally, Wilson's idealistic rhetoric during the war had raised the expectations of vast numbers of people around the world – the Irish, the Egyptians, the Indians, the Arabs, and many more – and the failure to fulfill those aspirations left bitter resentment. The delicate balance that Wilson sought to re-create, and the world organization that would maintain that balance of the Monroe Doctrine and the open door, conservative as they were, proved to be more than he could manage.

Warren G. Harding and the Republican Party succeeded Wilson in 1921, and while this was expected to return the United States to some form of “normalcy,” Hannigan shows that in many ways the new administration continued Wilson's policies, particularly in Latin America and Asia. United States troops remained in several Central American countries until the late 1920s, hoping to establish some kind of stability, as Wilson, Taft, and Roosevelt had attempted. The Washington Conference of 1921–22 worked to stabilize naval relations among the great powers. The United States claimed equality with Britain in capital ships although it never built up to the strength of the Royal Navy; Japan was prevented from achieving naval parity with either Britain or the United States. Thus a kind of status quo was maintained. The Nine Power Treaty also attempted to guarantee both the viability of a Chinese government and the open-door trade arrangement in China, an overt effort to maintain the status quo. In Hannigan's view, this marks a consistent American foreign policy from at least 1898 into the mid-1920s.