On December 25, 1978, the armed forces of Vietnam launched a full-scale invasion of Cambodia. That event marked a turning point in the first and only extended war fought between two communist regimes. The Vietnamese forced out Pol Pot's Khmers Rouge regime from its seat of power in Phnom Penh, but the ensuing war was a major source of international tension throughout the last decade of the Cold War. This book is the first comprehensive, scholarly analysis of the causes of the Vietnamese invasion. At its core are two separate but related histories covering the years 1930 to 1978. The first...