The US were partners in the ITER project until 1999. They then left the project for different reasons. While, at that time, the scientific and technical developments for the first (the “big”) ITER project had been successfully concluded, the political and economic boundary conditions for the project had deteriorated. Moreover, none of the partner countries had presented a proposal for a site. In essence, the project appeared too costly for realization: Russia was experiencing a serious economic crisis, and Japan, also in the throes of economic problems, had decided on a moratorium on the construction of major research facilities. The US had re-oriented its research activities, and the provision of clean energy on a timescale of fifty years did not appear to be a top priority. A shortlived, but widely publicized, theoretical prediction that ITER might not satisfy its stated goals probably also played a part in the decision of the US to abandon the project. In the meantime, ITER has become a leaner project, focusing exclusively on objectives lying on the critical path to a fusion power plant. Three concrete site proposals have been made, or are expected to be made official, in the near future, and three years of targeted research have further verified the design assumptions forming the basis of the project. The fact that Europe, Japan and Russia forged ahead successfully with the project has evidently re-established the credibility of the project in the US and rekindled their interest in participation. The scientific advisor of the US President has expressed his wish to follow closely the progress in the ITER negotiations and we already see the first steps taken by the US fusion community to re-enter ITER.