Advanced geophysical techniques developed in Hungary contributed immensely to the success of geological surveys carried out in the PRC after 1956. A group of Hungarian geophysicists played a pivotal role in discovering and exploring oil deposits in the Songliao Basin, which later became known as Daqing, the largest oil field in China. Based on declassified primary sources from Hungarian archives and firsthand testimony from people involved in the expedition, this article examines how Sino-Hungarian cooperation in Cold War activities evolved against the backdrop of the radicalization of Chinese politics and growing tensions between the Soviet Union and China. Taking the Hungarian geophysicists’ expedition as an example, the article explores the historical setting of early exchanges and the daily practice of scientific and technological interactions between the PRC and one of the closest East European allies of the Soviet Union.

This forum includes six commentaries on Lorenz M. Lüthi's book The Sino-Soviet Split: Cold War in the Communist World , published by Princeton University Press in 2008. Drawing on recently declassified documents and memoirs from numerous countries, Lüthi explains how and why the close alliance between the Soviet Union and the People's Republic of China fell apart in a remarkably short time, dissolving into fierce mutual enmity. Amassing a wealth of evidence, Lüthi stresses the role of ideology in the split, lending support to the arguments put forth nearly five decades ago by analysts like Donald Zagoria in his pioneering book on the Sino-Soviet rift. Six leading experts on Chinese foreign policy and Sino-Soviet relations discuss the strengths of Lüthi's book but also raise questions about some interpretations and omissions. The forum includes Lüthi's reply to the commentaries.