For 25 years, Cambodia's Khmer Rouge have avoided responsibility for their crimes against humanity. For 30 long years, from the late 1960s to the late 1990s, the Cambodian people suffered from a war that has no name. Arguing that this series of hostilities, which included both civil and external war, amounted to one long conflict--The Thirty Years War--Craig Etcheson demonstrates that there was one constant, churning presence that drove that conflict:...