The United States has gone to extraordinary lengths since the beginning of the nuclear age to inhibit—that is, to slow, halt, and reverse—the spread of nuclear weapons and, when unsuccessful, to mitigate the consequences. To accomplish this end, the United States has developed and implemented a wide range of tools, applied in a variety of combinations. These “strategies of inhibition” employ different policies rarely seen as connected to one another, from treaties and norms to alliances and security guarantees, to sanctions and preventive military action. The United States has applied these measures to friend and foe alike, often regardless of political orientation, economic system, or alliance status, to secure protection from nuclear atta...