The DSIRS (Division for the Social and International Relations of Science) of the BAAS (British Association for the Advancement of Science) is generally seen as the core of the Social Relations of Science (SRS) Movement in the British 1930s.2 The "social function" part has been widely studied. This is not the case for the "international function", neither for the participation of progressive scientists to international science. But activists from the SRS movement played the major part in the establishment of the World Federation of Scientific Workers (WFScW) and of the Unesco (United Nations Educational Scientific and Cultural Organization) Natural Science Department, which both took form in 1946.
They shared a common origin in the SRS movements and were seen at first as complementary by their founders. With the development of the cold war, they underwent opposite paths. The WFScW had a very limited scope in its first years. With Unesco, Needham put into practice new forms of international scientific co-operation along three main lines: the "periphery principle", no science without history of science, no scientific research without caring of the social aspects of science. He therefore managed to depart from an abstract idea of scientific internationalism.