Since the end of World War II, there have been four times as many civil wars as interstate wars. For a small subset of nations, civil war is a chronic condition: about half of the civil war nations have had at least two and as many as six conflicts. The author of this monograph, Dr. David Mason, seeks to spell out what social science research can tell us about how civil wars end and what predicts whether (and when) they will recur. After summarizing research on what factors define the risk set of nations that are susceptible to civil war onset, he presents an analytical framework that has been used, first, to explain and predict how civil wars end- whether in a government victory, a rebel victory, or a negotiated settlement-and, second, whether the peace will last following the termination of the conflict (or, alternatively, the nation will experience a relapse into civil war). Research suggests that the outcome of the previous civil war...