This paper asks how a scientific object functions in a diplomatic context by examining the distribution of radioisotopes by the United States to Japan in 1950. In particular, it aims to shed light on some material dimensions of the diplomatic roles that a scientific object can play. With diplomacy as its main focus, this study centers on those who received the radioisotopes (Japanese scientists) as well as the diplomats at the U.S. Department of State, rather than the Atomic Energy Commission. It shows the disparity between and the partiality of the conceptions of the radioisotopes by both parties. Drawing on Karen Barad’s posthumanist philosophy of science, this paper further examines some ramifications of the imported radioisotopes for the development of nuclear energy in Japan, which were not intended by U.S. diplomats nor anticipated by Japanese scientists. Highlighting the significance of these ramifications, this paper suggests expanding the scope of diplomatic studies in the history of science to include not only meanings, knowledge, and cultures embodied in objects in diplomacy, such as diplomatic gifts, but also aspects of material objects that are not susceptible to human expectations or interpretations.

The scientific object and material diplomacy: The shipment of radioisotopes from the United States to Japan in 1950