India and Pakistan declared themselves to be nuclear powers after they conducted weapons tests in 1998. This book is set up as a debate between the two authors over whether nuclearization has created a barrier to escalation during crises between the two nations -- the so-called nuclear stability theory, drawn from the U.S.-Soviet Cold War experience -- or whether it has instead created a shield for Pakistani adventurism and a risk of Indian overreaction. Analyzing past and present behavior by the two states, they try to apply the lessons of history to the future. Ganguly and Kapur agree that the two sides have managed their conflicts since 1998 without escalation but disagree on the extent to which this was due to nuclear deterrence. They also agree that the presence of nuclear weapons would make a failure to manage a crisis more catastrophic but disagree about whether nuclear arms increase or reduce the likelihood of such a failure. As for policy recommendations, the authors think India should refrain from developing ballistic missile defenses and that Pakistan should rein in its militant groups.