The invitation had been extended by Prime Minister Anthony Eden at a Summit meeting held in Geneva the year before. Three years after Stalin's death, the time seemed ripe for an easing of tensions between the two "blocks" and for a shift toward "the peaceful coexistence between states with differing political and social systems," to use Khrushchev's words to the Twentieth Congress of the Communist Party (February 1956).
Nikita S. Khrushchev, physicist Igor V. Kurchatov (in the middle, with beard) and Nikolai A. Bulganin on 26 April 1956 in Harwell, the Holy of Holies of Britain's nuclear research. It was the improbable beginning to what was to become a ''world fusion community.''
Why the sudden transparency? Neither history, nor archives nor published memoirs furnish a satisfactory answer. It is probable that Kurchatov was convinced that the resources of one nation alone would never be enough to solve the fusion challenge. There is some indication also that he was pleased to be able to show his hosts that—on a scientific and technological level—his country was at least as advanced as theirs.
Having contributed to the successful realization in the Soviet Union of the atomic bomb in 1949 and the ''H-bomb'' in 1953, Igor Kurchatov (1903-1960) was concentrating his energy on the ''thermonuclear synthesis problem''—in other terms, the mastery of fusion energy.