Paul M. Kattenburg, 81, a retired career Foreign Service officer who since 1973 had taught political science and international studies at the University of South Carolina, died June 12 while aboard a cruise ship in Moscow.

Dr. Kattenburg, who lived in Columbia, S.C., had been vacationing in Russia and was about to embark on a tour of the Volga River when he was stricken by a heart attack.

Dr. Kattenburg, who was born in Belgium, graduated from the University of North Carolina in 1943 and served in the U.S. Army during World War II, detailed to the Office of Strategic Services, the predecessor to the CIA. He received a master's degree in international relations from George Washington University in 1946 and a doctorate in the same discipline from Yale University in 1949.

He spent about a year engaged in postdoctoral field research in Indonesia before joining the State Department in 1950 as a research specialist on Southeast Asia. He later joined the Foreign Service and received assignments as a political officer in Saigon, Vietnam; Manila; and Germany.

Over the years, he became a key policy adviser on Vietnam and Asian regional affairs. His name appears in the Pentagon Papers, the once-secret government study of U.S. involvement in Southeast Asia, as an early dissenter of aspects of U.S. action in Indochina.

By the mid-1960s, Dr. Kattenburg was in Georgetown, Guyana, as counselor of embassy and charge of the mission. He was deputy coordinator of political studies at the State Department's Foreign Service Institute before retiring in 1973.

He taught at the University of South Carolina and was named professor emeritus in 1986. He also wrote books, articles and studies on diplomacy, U.S. foreign policy, human rights and international terrorism. In 1980, he published "The Vietnam Trauma in American Foreign Policy, 1945-75."

He also was a national faculty member of an undergraduate study-abroad program at the University of Pittsburgh; visiting fellow in international relations at Australian National University; and a resident scholar at the Hoover Institution, Arizona State University and Stanford University.

Survivors include his wife of 59 years, Mary Louise Clark Kattenburg, two sons, John Kattenburg and Charles Kattenburg, and a daughter, Jeanne Carlton, all of Columbia, S.C.; two other sons, Clark Kattenburg of Oakton and Richard Kattenburg of Martinez, Calif.; 10 grandchildren; and a great-grandson.