Years after General Moore retired from active duty in 1977, he visited Ia Drang with his North Vietnamese battlefield counterpart for an ABC documentary, publicly supported a global ban on the production and use of anti-personnel land mines, and likened the American invasion of Iraq to the protracted war in Vietnam, which, he wrote, ended after 10 years “with a hasty withdrawal just ahead of defeat.”

“His mantra,” his son David said, was “Hate war, love the American soldier.”

General Moore did both. Nicholas Proffitt, a former war correspondent, wrote of “We Were Soldiers Once” in The New York Times Book Review, “General Moore’s respect and affection for his troops is evident on every page, and one can understand why he became one of the legendary commanders in Vietnam.”

And why he hated war.

“As a glimpse into the abyss, into the bilious reality of war, it is a revelation,” Mr. Proffitt wrote. “As a reading experience, it’s a car crash of a book; you are horrified by what you’re seeing, but you can’t take your eyes off it.”

On Nov. 14, 1965, Hal Moore, at the time a lieutenant colonel and battalion commander, and about 450 troops from his First Battalion were ferried by helicopters to Landing Zone X-Ray, a field near the Drang River in South Vietnam, six miles from the Cambodian border. They stumbled on more than they had bargained for: three North Vietnamese regular army regiments that at times outmanned them 12 to 1.

“By midafternoon in 100-degree heat we were strongly outnumbered, taking heavy casualties in a cliffhanger fight to the finish,” the general wrote in a West Point yearbook.