WASHINGTON - Hans Heymann Jr., an economist who advised three US presidents on the Soviet Union and the Vietnam War - subjects he knew intimately as a key contributor to the top-secret history of the war known as the Pentagon Papers - died Jan. 10 at Sibley Memorial Hospital in Washington at 91.
He had complications from heart disease, said his daughter Kendra Sagoff.
Mr. Heymann began his career in 1950 as an analyst at the Rand Corp., a government contractor and think tank, and later served as a senior economics officer at the CIA and as a foreign policy adviser to the Ford, Carter, and Reagan White Houses.
Throughout his career, he specialized in the political environments and economies of Eastern Europe, the Soviet Union, and the southeastern Asian countries of Thailand, Laos, and Vietnam. He traveled widely for his assignments on arms transfers, civil and military aviation, and emerging technology.
In the 1960s, he was asked to work on a Defense Department research project that involved constructing a history of the Vietnam War - dubbed “the Pentagon Papers.’’
In an interview, Leslie Gelb, a former Defense Department official who oversaw the project’s day-to-day research, said he recruited Mr. Heymann for his wide-ranging expertise and scholarly integrity.
“I was always trying to steal smart people who knew some things,’’ Gelb said. “He had no axes to grind. . . . He was a real pro, the kind you wish you had more of today.’’
As a specialist on politics and economics, Mr. Heymann was responsible for fact-checking and editing many of the documents. The final product was a 2.5 million-word opus that examined the history of the US decision-making process on Vietnam policy from 1945 to 1967.
He retired from the CIA in 1984 and then lectured several more years for the Defense Department on international politics and economics.
Hans Bernard Richard Heymann Jr. was born in Berlin.
He was an economics graduate of Rutgers University. He received a master’s degree in Soviet economics from Columbia.