This report proposes initial discussion of a United States-led international policy of Uniform Deterrence of Nuclear First Use (UD). The purpose of such a policy would be to preserve the "firebreak" between nuclear and all other types of weapons, which since 1945 has been the key to preventing nuclear combat. The report analyzes both the role of UD in achieving its primary objective of deterring first use, and implementation of punishment for first use (preferably non-nuclear punishment) if deterrence fails. The discussion stresses the distinction between the deterrence of the use of nuclear weapons, which is the purpose of UD, and policies to discourage proliferation of the possession of nuclear weapons; but it contends that UD and anti-proliferation efforts should be complementary. The primary conclusion is that although implementation after a failure of deterrence would be difficult, it would not be impossible, and that UD can materially decrease the likelihood of first use in many cases. An open question is its acceptability, internationally and within the United States, which is why this report is an opening of discussion, not a closure.