“Very few civilians who were in Vietnam for more than a year could argue convincingly in support of the American presence,” Mr. Just wrote, observing that the Americans were seen by many South Vietnamese not as liberators but as new colonizers, taking the place of the French. In a 2017 interview with The New York Times, Mr. Just said his opinion about “that confounding war” had not changed.

He did not blame front-line soldiers for what he saw as the misjudgments of generals and political leaders. A major and a captain in the unit involved in the 1966 clash in which he was wounded were “quite simply admired, as men and as soldiers,” by their troops, he observed. “They were brave men, without being excessively reckless or self-conscious about it.”

But Mr. Just could be unsparing in judging the top brass. In a Times review in 1976, he panned “A Soldier Reports,” a memoir by Gen. William C. Westmoreland, the commander of United States forces in South Vietnam from 1964 to mid-1968. Mr. Just described the memoir, in which General Westmoreland placed much of the blame for the war’s outcome on cynical and defeatist journalists, as “petulant” and self-justifying, showing more concern about the war’s effects on his army than on his country.

In the 2017 interview with The Times, Mr. Just said General Westmoreland was wrong to think that the United States could ever have won a war of attrition. Perhaps, Mr. Just said, the United States might have “won” by waging total war against North Vietnam, using atomic weapons or carpet bombing until the North’s cities were destroyed and the countryside left barren. “But what kind of ‘victory’ would that have been?”

Ward Swift Just was born in Michigan City, Ind., on Sept. 5, 1935, to Franklin Ward Just and Elizabeth (Swift) Just. He grew up in Waukegan, Ill., and nearby Lake Forest. His father, like his grandfather, was the publisher of The Waukegan News-Sun. (The newspaper remained in the family until 1983, when Ward Just and several relatives sold their stock.)

He attended Trinity College in Hartford, Conn., found it a bad fit and left without a degree. He was then briefly a reporter at his family’s newspaper. For about a year he worked in the Chicago bureau of Newsweek before being assigned to the magazine’s Washington bureau, then headed by Benjamin C. Bradlee.

Mr. Just arrived in Washington just before the inauguration of President John F. Kennedy in 1961 — “a magical time” in the capital, as he recalled later. He worked briefly for Reporter magazine, then became a London correspondent for Newsweek.