While the concept “science diplomacy” is still in a fluid state, it has recently featured in international relations literature to underscore how the promotion of science and technology can facilitate bi- and multi-lateral state relations. This paper aims to explore the present relevance of science diplomacy and shed light on its ancestry. It will first recall recent scholarly work outlining its origins, and then look into history of science and technology studies emphasizing how their promotion has shaped international affairs. I will then consider if a new focus on science diplomacy activities could help us in re-interpreting key episodes in Cold War history. I conclude, also drawing on my recent book on NATO’s promotion of science and technology (Greening the Alliance), that greater emphasis on these activities, especially when understood as propelling informal/unofficial diplomacy channels, may significantly change our perspective.