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.
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.''