Stanley Karnow was one of the few journalists to witness the tragedy of Vietnam from beginning to end. He was there when the first U.S. troops were killed, in July 1959, and he stayed long after the last Americans were evacuated, in 1975, researching the war and the little-understood country. The result was a 750-page book, 1983’s Vietnam: A History, and an accompanying 13-hour PBS documentary. His expertise was such that in 2009, Gen. Stanley McChrystal contacted Karnow and asked him how the lessons of Vietnam could be applied to the fight in Afghanistan. “What we really learned in Vietnam,” he told McChrystal, “is that we shouldn’t have been there in the first place.”

Born in Brooklyn, Karnow grew up craving adventure, said The Washington Post. “I was a typical Jewish kid in a lace-curtained, cloistered environment,” he said. “It didn’t take me long to realize I wanted out.” World War II offered an escape. He joined the Army Air Forces, and spent much of the war in the mountains between China and India, monitoring the weather.

Karnow used his G.I. Bill money to enroll at a university in Paris in 1948, where he started to write dispatches for U.S. newspapers and magazines. Over the next decade, Karnow covered strikes and France’s war in Algeria, said the Los Angeles Times, but also had a “memorable, if regrettably brief, encounter” with Audrey Hepburn, and once interviewed a drunken Ernest Hemingway, who had just won the Nobel Prize for literature. “Oh, that little Swedish thing,” Karnow quoted him as saying. “Gave it to the mayor of Havana.”

In 1958, Time made Karnow its Southeast Asia bureau chief. Like many others, he initially supported U.S. involvement in Vietnam, believing it was necessary to stop the advance of communism, said the Associated Press. But as the conflict dragged on, and the American body count rose, he came to believe that the Vietnam War was unwinnable. His repeated criticisms of the war effort earned Karnow a spot on President Nixon’s enemies list—something the writer would later refer to as “one of the highlights of my life.”