Abstract On the 31st of October 1967 the Council of Ministers of the European Communities instructed a working party on scientific and technological policy, the PREST committee, to examine the possibilities for European technological cooperation in seven principal sectors. After a year long hiatus caused by a dispute over the British application to join the EEC, detailed proposals appeared in the ‘Aigrain report’. This document was sent to several non-member countries, including Britain, along with an invitation to participate. Following discussions in a committee of senior national officials drawn from 19 interested countries (the COST committee) a conference of Ministers responsible for science took place in 1971 at which agreements initiating seven so-called COST research projects were signed. This paper describes the events leading up to this final conference and the launching of the COST projects. These historical details are then used to examine the venture in terms of the concept of commitment to collaborate. Two different analytical perspectives are adopted: firstly we deal with the mechanics of COST as a formula for cooperation and consider the choice of research areas and the machinery used to implement the proposals; secondly we look at the relationship between technological cooperation in COST and the framework of the European Communities. We conclude that the structure of COST is very much related to its political milieu, but that few of the predicted advantages of Community research are likely to be realised. However, several of the difficulties associated with intergovernmental forms of cooperation do appear to have been at least partially solved. Finally, some reflections are offered upon the setbacks to the history of the projects and upon their mixed reception in terms of the conflicting goals of pragmatism, on the one hand, and an attempt, to promulgate a broadly based European science policy on the other.