What is an appropriate national security strategy for the post-Cold War period? For strategists, this question is especially relevant given the changes in today's world. My purpose here is to assess past national security strategies and recommend an appropriate strategy for the post-Cold War period. My assessment will focus on the most prominent of past national security strategies. These include isolationism, hemispheric defense, balance of power, and collective security arrangements. There have been others, but these strategies represent four of the most significant ones. Of the four, I consider collective security as the best strategy for U.S. national security during the post-Cold War period. But before discussing my reasons for selecting collective security, I'll first offer a brief assessment of the other strategies. America's first truly discernible national security strategy was isolationism. Its roots go back as far as the late eighteenth century. America's geographical location, and the fact it had achieved independence from Britain, set the nation on an initial course of isolationism. As an emerging nation, America consciously and at times, unconsciously, practiced isolationism.