There is a central tension at the heart of Gordon Barrett's important new book, China's Cold War Science Diplomacy, embodied by scientists in the People's Republic of China (PRC) and their relationship with the state. Top Chinese scientists in the early PRC had mostly received their training abroad in Europe and the United States. Their personal relationships and professional connections to international organizations and foreign scientists were essential to China's diplomatic efforts in the 1950s and 1960s and yet, as individuals, these figures were also utterly dispensable to the new regime.

In chapter five, Barrett makes the astute observation that, “People and personal relationships mattered. Scientists with involvement in multiple organisations, and specifically their friendships, served as the connective tissue between organisations” (205). The importance of these personal relationships, however, comes across most clearly in the book's discussion of British scientists like Howard Hinton, Kurt Mendelssohn, and Dorothy Hodgkin. Barrett examines their different approaches to their experiences visiting China both as scientists and, on their return to the UK, as some of the few people in the world with first-hand experience of the socialist country. What emerges from these case studies in chapter five are individuals with the agency to respond to China's overtures. On the other hand, constrained by the limitations of the available sources, the Chinese scientists who figure prominently in the book and their motivations remain largely enigmas.

An incident discussed in the book illustrates this central tension. In 1955, the philosopher Bertrand Russell and physicist Albert Einstein (who died before the formal publication of the manifesto) jointly issued a dire warning about the consequences of nuclear war. Many leading scientists from around the world signed the manifesto calling for the peaceful resolution of international conflicts. Russell personally reached out to geologist Li Siguang, who was the leading Chinese representative in the World Federation of Scientific Workers. Separately, fellow signatory to the manifesto Frédéric Joliot-Curie also wrote to Li Siguang. In 1955 Li happened to be going through a period of prolonged illness, but his poor health did not account for his silence to these appeals.

Both Russell and Joliot-Curie thought they were contacting an individual, a prominent Chinese scientist known to them through professional networks. Their letters, however, became part of a much larger discussion that reached all the way to Premier Zhou Enlai's office. Foreign Ministry officials held numerous meetings to discuss China's position on the Russell–Einstein Manifesto and drafted replies in Li's name. Months passed and, in the end, Li Siguang, the geologist and individual, made no appearance in any of the discussions. “Li Siguang,” the creation of officials in the Foreign Ministry and the Chinese Academy of Sciences, never replied to Russell's appeal (63–68).

The theoretical physicist Zhou Peiyuan had more agency as the Chinese representative to the Pugwash Conferences on Science and World Affairs in 1957–59. Zhou used the opportunity of the international conference to make new contacts, including Leo Szilard from the United States and Mark Oliphant from Australia. In Oliphant, Zhou found an interlocutor both open and sympathetic to socialist causes. While seemingly enjoying an unusual latitude at the conference (Zhou talked freely to other conference attendees without a hovering team of minders and translators), Zhou hardly operated as a free agent. Before he attended these conferences, Zhou received extensive briefings, including, in 1957, a meeting with Premier Zhou Enlai before his departure for Pugwash (71). All his interactions and background information on the scientists with whom he conversed then went into confidential after-conference reports submitted to the Foreign Ministry (75).

On the eve of the Great Proletarian Cultural Revolution, during which the Chinese Academy of Sciences shut down and many elite scientists suffered devastating political attacks and violence, China hosted two international scientific meetings in 1964–66. Preparations for these symposia involved both senior scientists and foreign relations personnel. The PRC spared no expense in hosting foreign scientists and providing roundtrip airplane tickets and other travel costs. The expensive changeable tickets that Argentine scientists received proved extremely helpful, allowing them to choose the dates of their departures from China. A right-wing military coup took place in Argentina shortly before the 1966 physics colloquium hosted by the Shanghai Scientific and Technical Association (146–47). The PRC went a long way to fostering goodwill by bearing the considerable costs of hosting these scientists from the Global South. Strong foreign attendance at the conferences belies the misconception of the PRC's diplomatic isolation during the Maoist years. Barrett convincingly shows that science was a critical way for China to reach out and engage with the outside world.

Barrett's work is part of a growing wave of scholarship that situates science in modern China in a transnational context. In China's Cold War Science and Diplomacy, Barrett provides a significant contribution to the literature on diplomacy in the early PRC by exposing the partisan nature of science and, at the same time, its centrality to China's engagement with the outside world. As the forestry scientist Liang Xi succinctly put it in the inaugural issue of the Scientific Worker (Kexue gongzuozhe) in 1948, “‘Science is inseparable from politics. Politics is just like soil and science is just like a plant. A plant can only grow with strength from the soil and science can only develop with strength from politics’” (23).