George McTurnan Kahin, 82, an expert on Southeast Asia who was a leading critic of Washington policy on the Vietnam War. Kahin served on the faculty of Cornell University for 37 years until his 1988 retirement. In the late 1960s he and John W. Lewis wrote "The United States in Vietnam," an influential book that helped to turn people in the university world against U.S. intervention in Vietnam. He and Lewis wrote that U.S. policy was based on a distorted view of Vietnam, which, they said, was "a single nation, not two." South Vietnam, Kahin and Lewis wrote, "constitutes an artificial creation whose existence depends on the sustained application of American power." A critic reviewing the book for the Nation said it was "the most lucid and fully documented study" of U.S. involvement in the war that had yet been done. Kahin, born in Baltimore and raised in Seattle, received his bachelor's degree in 1940 from Harvard, a master's degree in 1946 from Stanford and a doctorate in 1951 from Johns Hopkins. A pioneer in the field of Southeast Asian studies, he directed Cornell's South East Asia Program from 1951 to 1960. He was cited in a recent New York Times profile of Samuel R. "Sandy" Berger as a major influence on the foreign policy thinking of President Clinton's national security advisor. On Saturday in a Rochester, N.Y., hospital.