Gordon Barrett's excellent study of ‘how eminent Chinese scientists … became crucial international interlocutors for the early PRC [People's Republic of China] through their involvement in an interconnected cluster of organizations, events and networks’ (p. 3) during the first two or three decades of the Cold War throws new light on the importance that the revolutionary regime placed on international scientific collaboration. Dedicated Chinese scientists sought both to enhance national scientific capacity and to promote the social model that was under construction in China by working along with left-wing organizations and sympathetic individuals in the capitalist ‘West’ and the socialist world. Barrett describes in detail China's role in the World Federation of Scientific Workers in the first decade after the war, in the early Pugwash Conferences on Science and World Affairs up to the Sino-Soviet split in 1960, and in organizing huge international conferences in Beijing in the mid-1960s that explicitly targeted developing countries. The bridges built with a number of British socialists are given a chapter of their own.

I found this book particularly interesting, not simply for the quality of its scholarship, but also for the light it throws on the dynamics of transnational knowledge flows that are often obscured in studies of science diplomacy. Indeed the transnational scientific exchanges described by Barrett had a number of specificities that tethered them to the space–time context in which they occurred: this is a story of China's science diplomacy in the Cold War.

First question: is this science diplomacy at all? Or what form of science diplomacy is it? In its ‘standardized’ version, science diplomacy brings together scientists in different countries who collaborate on scientific questions that are of interest to them, and refined in conjunction with their national governments. In the positivist version of the paradigm, scientists define problems in a ‘universal’, value-free and objective language that facilitates dialog and cooperation between government officials tasked with pursuing ‘particular’ national interests. The science diplomacy described by Barrett has next to nothing in common with this characterization. It does not involve formal relationships between China and other states (as far as we can see). The collaboration is essentially between Chinese scientists who are tightly coupled with the Chinese Communist Party and its state apparatus, on the one hand, and left-wing, sympathetic organizations and individuals in other parts of the world, on the other. What is more, even when scientists from China got together with foreign colleagues, as in the Beijing science conferences, they made no attempt to bracket political convictions. Foreign visitors participating were harangued about the perfidy of the capitalist West and the Soviet Union, and the need to collaborate with China in an anti-imperial struggle. Transnational scientific collaboration rooted in scientific internationalism was an opportunity both to exchange scientific ideas and for Chinese scientists to promote their government's foreign-policy agenda to distinguished, sympathetic individuals from abroad. There is little or no formal inter-state cooperation in this mode of science diplomacy: it went no further than consular offices on both sides authorizing cross-border travel between Communist China and scientific visitors from foreign countries.

China's foreign-policy agenda in the Cold War defined what countries would be included in ‘international’ collaboration. Isolated by the United States and embittered by the Soviet Union's withdrawal of technical assistance in August 1960, there was no attempt to bridge geopolitical divides at the two major meetings in Beijing in the 1960s. On the contrary, international scientific exchanges were instrumentalized to drive a wedge between China and its ‘enemies’ and to enrol developing states scientifically and politically in Mao's agenda. One striking exception is Japan, which had a large delegation at the 1964 Beijing Science Symposium, an exception that is worth studying in detail.

The sciences discussed at this symposium reflected the priorities of the Chinese government (and developing countries), with special sections devoted to agricultural and medical sciences, as we might expect, and to science and engineering more generally. Noteworthy too are sessions on the social sciences: politics and law, economics, philosophy and history. These were surely used to promote Mao's thinking on dialectical materialism and the local interpretation of Marxist–Leninist thought. I also wonder what research questions were not allowed to be discussed, especially in nuclear and space sciences and engineering. Barrett tells us that Nie Rongzhen, who was responsible for China's civil and military nuclear programmes at the time, was actively engaged in organizing the two international meetings in Beijing. But we know nothing about the censorship that he imposed on scientists who discussed China's progress in nuclear physics at these conferences or earlier during Pugwash meetings. What knowledge was shared or denied with, say, Mark Oliphant, who built a cyclotron in Birmingham University, who worked in the Manhattan Project, who went on to direct a research group at the new Australian National University after the war, and who visited China in 1964? Reversing the arrow of transmission, it would also be useful to know more about the impact on Chinese science and science policy of exchanges with some of Britain's leading crystallographers, people like J.D. Bernal, Kathleen Lonsdale and Dorothy Hodgkin.

This is an extremely engaging and important book for scholars interested in the first decades of Mao's rule in China. It emphasizes the importance the regime gave to transnational scientific exchanges with sympathetic foreign scholars, defying the US attempts to isolate it after the Korean war up until the early 1970s. It is also a major contribution to studies of science diplomacy precisely because it describes (in as much detail as the archives consulted permit) a highly politicized mode of international scientific collaboration led by a ‘developing’ country in its first decades of state formation. The measures taken by Chinese scientists and by the CCP to mobilize science and technology to transform and modernize an agrarian society, and to enroll politically sympathetic scientists from abroad in its national and global ambitions, remind us of the need to define carefully what we mean by science diplomacy. They also oblige us to situate science diplomacy in its temporal and geopolitical context, and to tease apart the specificities of its collaborative practices undertaken in the shadow of (sometimes determining) national political agendas.