When the Twentieth Congress of the Communist Party of the Soviet Union convened in February 1956, the new direction in Soviet foreign policy already was evident, but the congress played a significant role by articulating and approving the changes in interpretation of Marxist-Leninist doctrine that supported a relaxation of tensions. In the Third World, as in all other arenas of the Cold War, no development so profoundly affected the foreign policy of the Soviet Union in the 1960s, 1970s, and 1980s as its conflict with China. The Kennedy administration, which came to power in 1961, pledged an activist response to the Soviet challenge in Europe and the Third World. The Sino-Soviet conflict escalated further in the early 1960s as a result of incidents along their long border. In the new spirit of glasnost, pointed references to the errors and shortcomings of the Brezhnev-era “old thinking” began to appear in the Soviet press.