If the build-up of nuclear weapons was a significant factor in maintaining the "long peace" between the United States and the Soviet Union, will the spread of nuclear weapons beyond these two superpowers stabilize or disrupt international relations. In this book, two scholars of international politics debate the issue. Kenneth Waltz argues that fear of the spread of nuclear weapons is unfounded - "more may be better". Nuclear proliferation may be a stabilizing force, as it decreases the likelihood of war by increasing its costs. Scott Sagan, however, argues that nuclear proliferation will make the world less stable - "more will be worse". Nuclear-armed states may not possess the internal structures that would ensure safe and rational control of nuclear weapons. Written for a general audience, this book is intended to help the public understand more clearly the role of nuclear weapons in the new world order.