Why did the United States intervene in World War I, breaking with its
long tradition of noninvolvement in European political and military
conflicts? During the 1920s and 1930s, many “revisionist”
historians argued that American efforts to protect its trade with the
Allies ultimately led to intervention. The logic of the revisionist
position closely parallels the contemporary liberal case that
interdependence promotes peace but arrives at different conclusions about
the relationship between trade and conflict. Historians have largely
abandoned this economic interpretation of American intervention, but data
on the impact of the wartime export boom on the United States suggest that
it should be reconsidered. The export boom was so large that it would have
been difficult to ignore, and its progress corresponds to the timing of
important decisions leading to American belligerency. An analysis of
congressional voting on war-related measures also suggests that export
income helped shape politicians' views of the war.I would like to thank Katherine Barbieri, John Coogan, David
Clark, Jeffry Frieden, Jack Levy, Brian Lai, Timothy McKeown, David
Painter, Strom Thacker, and participants in the world politics workshop at
Binghamton University, the political economy workshop at Harvard
University, and the Department of Political Science at the University of
Wisconsin, Madison, for their many comments and suggestions on earlier
versions of this article. Lisa Martin and several anonymous reviewers at
International Organization also made many valuable suggestions. I
am especially grateful to Thomas Walker, whose good-natured skepticism
prompted me to write this paper. An earlier version of this article was
presented at the 2005 annual meeting of the American Political Science
Association. Any remaining errors and misinterpretations are my
responsibility.