This Article analyzes state communications to the United Nations Security Council during episodes of serious interstate conflict. In Part I, I explain the basis in the U.N. Charter for state communications about their uses of force. I then advance three hypotheses regarding state practice during and after the Cold War. I hypothesize that overall state communications should have increased after the Cold War; that states should be advancing more diverse legal justifications for their uses of force; and that states should be focusing more on the jus in bello than during the Cold War. An analysis of several hundred state communications drawn from a fifty-year period provides only limited support for these hypotheses. Patterns in state justifications to the Security Council have not changed markedly, and states remain overwhelmingly focused on self-defense as a legal justification.