Crossing boundaries, forging unity: nuclear medicine and science diplomacy in Cold War Europe.

This article explores the emergence of nuclear medicine as a clinical research field in post-war Europe, focusing on the shaping of its disciplinary boundaries in the context of geopolitical divisions. It examines how this speciality was negotiated and established, highlighting the role of international exchanges involving researchers, radioisotopes and technologies. By bringing together physicists, radiologists and internists, nuclear medicine gained momentum in the 1950s, leading to the formation of first dedicated scientific societies, conferences and journals. Physicians working in Austria played an influential role in this identity-building process on the European level. They benefited from the networks of the International Atomic Energy Agency in Vienna, the country's political neutrality and their early emphasis on thyroid diseases. We argue that nuclear medicine emerged out of scientific-diplomatic practices that unified this diverse field of research while also setting it apart from more established clinical specialities. We will trace how physicians and medical facilities in Austria came into play as partners on both sides of the Iron Curtain and navigated these intertwined diplomatic and disciplinary dynamics, facilitating intra-European cooperation on epistemic, political and social levels.