We face many foreign policy decisions--how to respond to the fighting in Afghanistan, Lebanon, Nicaragua, Salvador, Angola, Kampuchea, the Philippines and soon, perhaps, South Africa--that involve the legality of intervening in a civil war. The international law journals are full of scholarly discussions on this subject. They are hard for non-scholars to follow. They disagree sharply, as scholars are wont to do, in their argumentation and conclusions. For readers who are not scholars of international law, this article tries to explain how the rules have evolved, where they now stand, and how they might be clarified to relieve the rising tension between the principle of nonintervention and the human rights of self-determination and open democratic elections.