The 1994 Summit of the Americas marked a high point in hemispherism-our label for the active attempt by the nations of the Western Hemisphere to form regimes of cooperation with one another. To explain why hemispherism has not been a more powerful trend in the last 200 years, structural, interest, and cultural variables are relevant but insufficient factors. An important and often overlooked obstacle to hemispherism has been contrarian ideas. Specifically, constellations of intellectual traditions that question the value of hemispheric cooperation have dampened both the demand for and supply of such regimes. Only when these antihemispheric intellectual traditions were in retreat-the late nineteenth century, the mid twentieth century, and the early 1990s-has hemispherism flourished. We posit three mechanisms through which intellectual traditions can decline, thus generating a modified cognitivist argument that can supplement power-based and interest-based explanations of regime formation and robustness.
