The issue of Unesco's relations with the Federation was discussed throughout the founding conference. Among the delegates, many were close to Needham. Various participants underlined the similarities between the object of both bodies, and some were puzzled about the small space left by Unesco to the Federation. In his address to the conference, Needham presented the first Unesco science programme, and proposed that Unesco should support the Federation through a formal agreement, similar to the one being negotiated with ICSU. Later, he insisted on the complementary functions of Unesco and WFScW, between an inter-governmental agency and a rank-and-file scientists movement, more radical and freer.
It seems than Joliot and Crowther were more politically reluctant about close relations between the Federation and Unesco, even from the beginning. They feared about the independence of the Federation. They expected mainly material and financial support from Unesco, and the question of an office for the Federation inside Unesco House in Paris was discussed as early as the founding conference in July 1946.
One year after its foundation, the Federation had only 16 members from 13 countries. Due to the lack of money and to the growing Cold War, the Federation hardly existed for the first two years. The first General Assembly was scheduled in Prague, September 1948. It had difficulties to gather the 9 associations that the constitution required for the General Assembly to be valid. American associations had left. British and French scientists represented around 80% of the roughly 24 000 claimed members of the Federation. It has organized commemorations for Langevin and for Rutherford, in London and Paris, published and circulated the manifesto adopted in July 1946, worked for Unesco, drafted a "Charter for Scientific Workers", and rose the problem of secrecy in science. After the General Assembly, the activity continued not to be very important.
The Federation underwent a severe crisis in 1949 and 1950, related to the split within the World Federation of Trade Unions (WFTU). Some Western associations left the Federation. The AScW had to choose between its affiliation to the Trade Union Congress and an agreement between the WFScW and the WFTU. It tried to push forward a new, non-communist leadership, but failed. Joliot, Bernal, Crowther and Biquard kept their positions. The Federation had to renounce to sign the agreement with the WFTU, which was publicly regretted by Joliot and some members.
The second General Assembly had to be postponed from 1950 to 1951. It was unable to meet in Paris. The visas were denied to Eastern delegates, and two meetings were held simultaneously in Paris and Prague.
The situation change completely when the Russians finally decided to join the Federation in 1952, together with the Polish and the Hungarians, but it is another history.
Meanwhile, Needham was organizing and developing the Natural Sciences Department of Unesco. He tried to operate a multi-faced programme during the two years he headed this Department, with three main lines coming from the SRS movement: the periphery principle; the inclusion of the social aspects of science within the Department; and the inclusion of history of science. Another aspect had the same origin: the necessity for the Unesco Science Department to include the applications of science.13 It provoked some conflicts with the UN Social and Economic Council, which wanted Unesco to limit itself to basic sciences.
A further dimension of Needham's agenda could also be related with the social function of science: the importance given to the environmental problems, which will become the core of Unesco scientific programmes in the 1950s. The first attempt of an international laboratory was for the Amazonian Hylea in 1946, followed by the proposal of an Arid Zones Institute in 1947. A scientific conference was held in October 1948 to establish the International Union for the Protection of Nature.