The second half of the 20th century featured a strategic competition between the United States and the Soviet Union. That competition avoided World War III in part because during the 1950s, scholars like Henry Kissinger, Thomas Schelling, Herman Kahn, and Albert Wohlstetter analyzed the fundamental nature of nuclear deterrence. Decades of arms control negotiations reinforced these early notions of stability and created a mutual understanding that allowed U.S.-Soviet competition to proceed without armed conflict. The first half of the 21st century will be dominated by the relationship between the United States and China. That relationship is likely to contain elements of both cooperation and competition. Territorial disputes such as those over Taiwan and the South China Sea will be an important feature of this competition, but both are traditional disputes, and traditional solutions suggest themselves. A more difficult set of issues relates to U.S.-Chinese competition...