The articles in this special issue of the journal succeeded in meeting the core objective set out in the introduction: to refine, deepen, and extend previous studies of the role of ideas in the end of the Cold War. In particular, they confront more forthrightly than past studies a major challenge of studying ideas in this case; namely, that ideas, material incentives, and policy all covaried. Two other important problems for those seeking to establish an independent role for ideas remain to be addressed in future studies. Facing those problems as squarely as the contributors to this issue have faced the covariation problem will yield major benefits for the study of ideas in this case and in international relations more generally.