The outbreak of the Third Indochina War in late 1978 confirmed what everyone had known for a long time — the Sino–Soviet alliance upon which the unity of the communist world had turned since 1950 was dead. The Soviet invasion of Czechoslovakia in 1968 had first revealed the deep rift dividing Moscow and Beijing as they now faced off aggressively in Central Asia. A second fault line had also emerged further to the east since the early 1970s between Vietnamese and Cambodian communists. Mutual suspicions and fears of encirclement came into the open with the American withdrawal from Indochina in 1975; this rapidly transformed into conflict as the Chinese suspected the Vietnamese of siding with the Soviets, and the Soviets watched as the Chinese now tried to contain them in collaboration with the Americans. The two fault lines connected in 1978 when the Vietnamese invaded a now communist Cambodia and China's leader, Deng Xiaoping, travelled to Washington before ordering troops into Vietnam to ‘teach this country’ a lesson. Upon his return to China, Deng ordered his divisions into northern Vietnam. The first war in world history among communists had just broken out where two other major conflicts had preceded it — in former French Indochina.

Scores of books and articles have been written about the Third Indochina War and much of it is very good (To name but a few: Nayan Chanda, Brother enemy: The war after the war; Grant Evans and Kelvin Rowley, Red brotherhood at war: Cambodia, Laos and Vietnam since the fall of Saigon; Andrew Mertha, Brothers in arms: Chinese aid to the Khmer Rouge, 1975–1979; and Arne Westad and Sophie Quinn-Judge, The Third Indochina War: Conflict between China, Vietnam and Cambodia, 1972–79). The strength of Xiaoming Zhang's new book, Deng Xiaoping's long war, is that it adds new information to the Chinese side in several ways. First, the author trawls a large body of Chinese language military histories, memoirs, and document collections. Second, he provides a very useful account of the military conflict between the Vietnamese and the Chinese, with particular attention paid to the Sino–Vietnamese border. Xiaoming Zhang does a fine job of using new Chinese information to show how border problems connected with the wider dimensions of the communist meltdown. Third, his sources also allow him to show the extent to which Deng Xiaoping, the man who finally took over the leadership in China following Mao Zedong's death in 1976, accelerated his country's opposition to the Vietnamese occupation in Cambodia as part of his wider strategy of taking on the perceived Soviet threat in Central Asia and in the South China Sea. Xiaoming Zhang carefully explains Deng Xiaoping's central role in pushing through plans to invade northern Vietnam, even before Hanoi sent its troops into Cambodia. The border conflict was a major point of concern for the Chinese leadership in its decision-making.

This is an important book. Specialists of the Third Indochina War will be grateful to Xiaoming Zhang for shedding new light and information on the Chinese side, in particular on the military aspects of the confrontation and how this shaped relations at the local level along the Sino–Vietnamese border. The information the author provides will also help us achieve a better understanding of the complex, interconnected nature of one of the most important wars in twentieth-century world history. On that note, one small quibble: Xiaoming Zhang argues that the Sino–Vietnamese war was one of the last chapters of the Cold War. He may be right. But after finishing this book and delving into scholarship on this conflict, I couldn't help but wonder whether this war among communists symbolised the end of the Cold War in the Eurasian half of the international system, a decade before the Berlin Wall fell in Europe. Ideology meant little as Chinese troops poured into Vietnam and Vietnamese invaded Cambodia. The Americans were no longer ‘containing’ China as in 1950 — the Chinese were using the Americans to contain the Soviet Union for reasons very different from those defining a Cold War. Ideology as a component of formulating diplomacy was dead. And it had been for a long time.