From the late 1940s to the late 1950s the WPC, with its large budget and high-profile conferences, dominated the peace movement, to the extent that the movement became identified with the Communist cause. The formation of the Campaign for Nuclear Disarmament in Britain in 1957 sparked a rapid growth in the unaligned peace movement and its detachment from the WPC. However, the public and some Western leaders still tended to regard all peace activists as Communists. For example, US President Ronald Reagan said that the big peace demonstrations in Europe in 1981 were "all sponsored by a thing called the World Peace Council, which is bought and paid for by the Soviet Union", and Soviet defector Vladimir Bukovsky claimed that they were co-ordinated at the WPC's 1980 World Parliament of Peoples for Peace in Sofia. The FBI reported to the United States House Permanent Select Committee on Intelligence that the WPC-affiliated U.S. Peace Council was one of the organizers of a large 1982 peace protest in New York City, but said that the KGB had not manipulated the American movement "significantly." International Physicians for the Prevention of Nuclear War was said to have had "overlapping membership and similar policies" to the WPC. and the Pugwash Conferences on Science and World Affairs and the Dartmouth Conferences were said to have been used by Soviet delegates to promote Soviet propaganda. Joseph Rotblat, one of the leaders of the Pugwash movement, said that although a few participants in Pugwash conferences from the Soviet Union "were obviously sent to push the party line ... the majority were genuine scientists and behaved as such".