The creation of the International Astronomical Union as a result of scientific diplomacy

After World War I, the foundation of the International Astronomical Union delimited a space for a new form of internationality, which led to a rapid change in the way astronomical research had previously been pursued. This structure was to be a sort of parliament of astronomical nations which planned to supervise scientific programs and to rationalise inter-observatory cooperation. In this article, I will discuss the sociological aspects of this institutional process and introduce the idea of `scientific diplomacy'.