In the late 1970s, the major fusion programmes worldwide (those run by national laboratories of certain European countries under contract of Association under the EURATOM Treaty, and those run by the governments of Japan, the then Societ Union, and the United States of America), had all designed and were building new large tokamaks aiming to explore the physics needed to approach reactor conditions.

They then started to explore what to build next assuming these experiments were a success, and to scope out the future development programme needed to commercialise fusion power. After some initial explorations on their own, the International Fusion Research Committee (IFRC) of the IAEA proposed that the programme participants work together on INTOR (International Toroidal Reactor). Participants in these programmes then began to meet twice per year for a couple of weeks to pool expertise and gradually evolve a design for this next step experiment. Such an approach, though very useful, was rather slow at evolving a meaningful engineering design that would fit the needs of the home programme well. Each programme therefore set up its own design team to study the engineering design of a next step device in more detail: FED (Fusion Engineering Device) which later led via TFCX (Tokamak Fusion Core Experiment) in a series of cost-cutting attempts to TIBER (Tokamak Ignition/Burn Experimental Reactor) in the USA, NET (Next European Torus) in Europe, FER (Fusion Engineering Reactor) in Japan, and OTR (Experimental Thermonuclear Reactor) in Russia. These teams continued to contribute to INTOR but agreement on what to build next was slow to come.

At the time the arms race between the USA and Soviet Union was having significant economic implications particularly on the latter. Joint activities were needed that would defuse the tension and begin the economic integration of the Soviet Union in the World economy. The next step in fusion development was ideal for this: the end result was not defence-related but involved important leading edge technologies whose development costs and knowhow would be shared, the technical information exchange between the programmes had been open since 1956, the potential commercial gains were far in the future, and the programmes had reached comparable levels of development such that there was much mutual respect between the researchers, and no clear leader. So Premier Gorbachov on the advice of Acad. Evgenij Velhikov and others, and after previously talking the matter over with President Mitterand of France, took the initiative to propose at the Geneva Superpower Summit with President Reagan in November 1985 that an international project between Europe, Japan, USA and the USSR be set up to develop fusion energy for peaceful purposes by the joint construction of the next step device.

This initiative became particularly important following the standoff over nuclear disarmamanent at the Rekjavik Superpower Summit in October 1986, and immediately thereafter the United States, in consultation with Japan and the European Community, responded with a proposal on how to implement such an activity. The ensuing discussions resulted in the establishment of a collaboration under the auspices of the IAEA known as ITER - the International Thermonuclear Experimental Reactor - and also meaning "The Way" in latin.

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