Many scholars have ignored the concept of ‘national interest†simply because no logical, systematic means of dealing with this key aspect of international politics has been available. A new approach to defining national interest forms the basis for this study of presidential decisions on U.S. involvement in foreign wars. Professor Nuechterlein looks at various crisis situations to determine what defense, economic, world order, and ideological interests are at stake; he identifies sixteen cost/risk and value factors that affect the U.S. view of which interest is most vital in a given situation. In any dispute, it is the interest that is considered vital—too important to compromise—that is the key element in crisis decisions. Professor Nuechterlein uses his analytical framework to examine the ways Presidents Wilson, Roosevelt, Truman, Johnson, and Nixon perceived the national interest when making their decisions to begin or extend U.S. war involvement. He assesses the value of National Security Council participation in the decision-making process and presents case-study analyses of three imminent U.S. foreign policy concerns—Quebec’s possible separation from Canada, the Panama Canal Treaty, and the potential for race war in South Africa—with an epilogue on the challenges facing Carter. The author suggests that the most important U.S. national interest in the future will be economic, with energy conservation a top priority.