Douglas Pike, 77, a historian, archivist, university professor and retired Foreign Service officer who was a leading authority on the Vietnam War, died May 13 at a hospital in Lubbock, Tex., after a stroke. He lived in Lubbock.

He wrote at least a half-dozen books and numerous articles that were published in scholarly journals and in the general press. He was recognized as a dispassionate and non-ideological authority on the Vietnam conflict, and especially on the role and history of the communist armed forces of Southeast Asia.

Mr. Pike had been affiliated since 1997 with Texas Tech University in Lubbock, where he was a history professor and associate director of the university's prestigious Vietnam Center.

The center houses much of the historical materials Mr. Pike had been compiling since 1960, including 7 million pages of documents in 15,000 books and 15,000 monographs. The collection not only includes U.S. government documents, but notes and diaries of political and military figures as well as an unsurpassed collection of North Vietnamese documents.

Mr. Pike also had published the quarterly Indochina Chronology, which he founded in 1982. He published it until last year.

In the mid-1960s, MIT Press published two of his books, "Vietcong: The Organization and Techniques of the National Liberation Front of South Vietnam" and "War, Peace and the Vietcong."

Both books were hailed by critics of all political persuasions. His 1986 book, "PAVN: People's Army of Vietnam," which was published by Presidio, was reviewed in The Washington Post by Harry G. Summers Jr., a retired Army colonel, Vietnam veteran and historian. Summers called it "without a doubt the best work available" on the subject.

Mr. Pike was born in Minnesota and raised in North Dakota. A 1953 journalism graduate of the University of California at Berkeley, he received a master's degree in international communications from American University. He had studied at the University of North Dakota and the Massachusetts Institute of Technology.

He served with the Army Signal Corps in the Pacific during World War II. He was in the early wave of soldiers that entered a defeated Japan, and he wrote about the bombing of Hiroshima for the Stars & Stripes military newspaper. After the war, he worked for the United Nations and was a civilian Army employee.

Mr. Pike entered the State Department's Foreign Service in 1960 and was posted to Saigon, South Vietnam, with the U.S. Information Agency. He later served in Hong Kong, Taipei and Tokyo while continuing to collect documents and researching Vietnam.

In the mid-1960s, he ran a psychological warfare unit in Vietnam. During this tour, he collected communist documents and interviewed war prisoners. He also conducted a study of the North Vietnamese Tet Offensive of 1968 and focused on the execution of thousands of South Vietnamese civilians in Hue -- who Mr. Pike maintained were killed for political reasons by the North Vietnamese.

The State Department recognized his expertise on Vietnam, sending him to conferences and on speaking tours. After tours elsewhere in the Orient, he served a last time in Vietnam in 1973 and 1974 -- and retired from the Foreign Service in 1982.

He worked for the Congressional Research Service and the Defense Department before joining the staff of the University of California at Berkeley, where he founded the Indochina Archive. In 1997, after encountering budget problems at Berkeley, he joined Texas Tech and its Vietnam Center.

Mr. Pike, whose views were swayed by historical evidence rather than political preconceptions, could look back on Vietnam and his quest for its mysterious truths in the long, mysterious and divisive conflict.

In 2000, he was quoted in The Post as saying that there was a "consensus that none of us had it right back then. Fifty years from now, we'll probably see the issues clearly. But we still won't know the Truth."

Survivors include his wife of 45 years, the former Myrna Johnson, of Lubbock; two sons, Andrew, of Las Vegas, and Ethan, of Washington; and a daughter, Victoria Pike Bond of Pleasant Hill, Calif.