At some time between 1949 and 1951, Pol Pot and Ieng Sary joined the French Communist Party. In 1951, the two men went to East Berlin to participate in a youth festival. This experience is considered to have been a turning point in their ideological development. Meeting with Khmers who were fighting with the Viet Minh (but subsequently judged them to be too subservient to the Vietnamese), they became convinced that only a tightly disciplined party organization and a readiness for armed struggle could achieve revolution. They transformed the Khmer Students Association (KSA), to which most of the 200 or so Khmer students in Paris belonged, into an organization for nationalist and leftist ideas.