In China, academic research is not something you can do freely. Some taboos exist, such as the study of Sino-North Korean relations. For a long time, research into these relations has been troubled by a double whammy of sensitivity and lack of archival materials. Shen Zhihua and Yafeng Xia's long-awaited book, A Misunderstood Friendship: Mao Zedong, Kim Il-Sung, and Sino-North Korean Relations, 1949–1976, has beaten the odds and emerged to be the best documented, path-breaking monograph in the field of Sino-North Korean studies.

The authors make it clear that they want to correct the long-held “fictitious legend” (p. 1) about Sino-North Korean friendship and reconstruct an accurate account of the relationship. The central thesis of the book is that there were many contradictions, disputes, deceptions and rivalries between the two countries beneath the surface of this friendship.

The rich sources of archival documents are a main selling point of the book. Shen is an excellent and dedicated collector of archive materials, and has established himself as an influential critical historian in Russia-related studies in China. Shen and Xia tap into multiple archival sources – from Russia, China, East European countries and the US – to portray the dark side of relations between China and North Korea. Drawing heavily on these hard-won archival documents, the authors chronicle in detail some notably unpleasant interactions between the two countries’ leaders, parties and governments. They cover almost all the significant events in their relations, ranging from the Korean War, through the 1956 Sino-Soviet joint intervention in the Workers’ Party of Korea's internal affairs, the withdrawal of the Chinese People's Volunteer Army from North Korea in 1958, North Korea's wild swing between China and the Soviet Union in the 1960s, to the Sino-US rapprochement and its impact on Sino-North Korean relations. To a large extent, the quality of each chapter hinges on the availability of archival documents. Since the Chinese ministry of foreign affairs has only declassified diplomatic documents dating from 1965 and earlier, the account of the interactions between China and North Korea in the 1950s and first half of the 1960s is solid and convincing, whereas the interpretation of their relations from 1966 to 1976 is relatively weak and inconclusive.

Even though this book is well documented, some key archival materials that can best settle remaining questions over some critical issues are still missing. For example, the book does not offer detailed minutes of the important meetings between Mao Zedong and Kim Il Sung on 13 May 1950 and 9 November 1954, nor does it lay out the content of the Sino-Korean Border Treaty signed on 12 October 1962 and the full list of the eight-point demand Pyongyang asked China to present to the US government in 1971. Since North Korea's diplomatic materials are inaccessible and Chinese archives are limited and highly selective, the authors had to use third parties’ archival documents to elaborate certain events, but the wide use of third parties’ indirect information inevitably undermines the reliability of the book.

The authors demonstrate tremendous courage in tackling this formidable academic challenge and “seeking truth from facts,” but their informed analyses are not free from problems. The authors claim, “We argue that the Sino-North Korean special relations can be traced to 1958, when the Chinese People's Volunteer Army withdrew from North Korea” (p. 4). I wonder why the special relations can be traced to 1958 rather than to the outbreak of the Korean War in 1950, when China sacrificed so much to save the North Korean regime. The authors also insist that Stalin did not want China to join the Korean War because he was concerned that China's entry might undermine the Soviet Union's exclusive control over North Korea (p. 39). In addition to this concern, I argue, Stalin might have feared that China's intervention would upend the Yalta system, which secured Soviet gains in the Second World War. As to the question of why in 1961 North Korea turned to China right after signing the alliance treaty with the Soviet Union, the authors simply attribute the change to Khrushchev's cancellation of his overdue visit to Pyongyang and his censure of Stalin's personality cult at the 22th Congress of the CPSU in October 1960, which Kim perceived as a direct criticism of himself and Mao Zedong (p. 149). In fact, North Korea's decisively leaning toward China had more to do with its plan to initiate border territory negotiations and persuade China to concede a significant area of land in the China-controlled Changbai mountain region the following year.

Just portraying Beijing–Pyongyang relations in a positive light, as China's text books do, is biased, but overwhelmingly focusing on the dark side of the relations is also prejudiced. Shen and Xia endeavour to balance against the overly positive official narrative, but they have perhaps overcompensated. However, their book should definitely appear on the reading list of anyone who really wants to understand the evolution of Sino-North Korean relations.