Book excerpt: From the former secretary of defense and author of the acclaimed #1 bestselling memoir, Duty, a candid, sweeping examination of power, and how it has been exercised, for good and bad, by American presidents in the post-Cold War world. Since the end of the Cold War, the global perception of the United States has progressively morphed from dominant international leader to disorganized entity. Robert Gates argues that this transformation is the result of the failure of political leaders to understand the complexity of American power, its expansiveness and its limitations. He makes clear that the successful exercise of power is not limited to the ability to coerce or demand submission, but must also encompass diplomacy, strategic communications, development assistance, intelligence, technology, and ideology. With forthright judgments of the performance of past presidents and their senior-most advisers, insightful ­firsthand knowledge, and compelling insider stories, Gates’s candid, sweeping examination of power in all its manifestations argues that U.S. national security in the future will require abiding by the lessons of the past, reimagining our approach, and revitalizing nonmilitary instruments of power essential to success and security.