Looking back a half century, to when they were young officers, their memories of the battle of Hue are still fresh.
"What I saw was probably the most intense ground fighting on a sustained basis over several days of any other period during the war," says Howard Prince, an Army captain who worked with South Vietnamese forces.
"We were under fire, under heavy fire," says Jim Coolican, a Marine captain.
Mike Downs, another Marine captain recalls, "We didn't know where the enemy was, in which direction even."
The enemy forces were everywhere. Inside houses and tunnels and in the sewer system, and they captured the citadel, a massive castle-like expanse in this city that was once the imperial capital, just north of Saigon.
It was the bloodiest battle of the Tet Offensive and also the entire war — and it all took American officials completely by surprise, says author Mark Bowden.
"You had the incredible rose-colored reports coming from Gen. William Westmoreland, who was the American commander in Vietnam," says Bowden, who wrote the recent book Hue 1968. "[He was] assuring the American people that the end was near, that the enemy was really only capable of small kinds of ambushes in the far reaches of the country."
But then came Tet. North Vietnamese troops and their Viet Cong allies swept throughout cities and towns, into military bases, even breaching the walls of the U.S. Embassy grounds in Saigon.
Back in Washington, President Lyndon Johnson called his defense secretary, Robert McNamara, and asked for an explanation.
McNamara told him that the American people would realize that the enemy forces were stronger than they had been told, that the Pentagon was searching for targets but the Vietnamese enemies were still a "substantial force."
A substantial force. But just six weeks earlier, a top White House official told New York Times reporter Gene Roberts the war was already over.
Roberts was heading off to Vietnam, so National Security Adviser Walt Rostow gave him a story idea. He told Roberts about a new U.S. agricultural program, Roberts recalls, "which would double the rice yields in Vietnam and would win the peace now that Americans had won the war."
The battle for Hue
Far from winning, the Americans were barely holding on in Hue. Roberts saw terrified refugees, wounded marines and heavy gunfire. His first story said the Marines controlled just two blocks of the city. Reinforcements were needed. Not just troops but artillery.
That was slow in coming. Jim Coolican, a Marine captain during the battle, said his own military superiors didn't understand how desperate the Marines were. The Americans were badly outnumbered.
"The reaction we got and I'm paraphrasing now, but the reaction we got was that we were overreacting. It isn't that bad," remembers Coolican.
More reporters showed up at Hue, including some from NBC. The pictures showed a desperate scene, talking to a Marine under fire who said he just wanted to go home.
Still, Westmoreland downplayed the situation, telling reporters the real enemy objective was a large and remote Marine base at Khe Sanh.
"In my opinion," Westmoreland told reporters, "this is diversionary to his main effort, which he had planned to take place in Quang Tri Province, from Laos toward Khe Sanh and across the demilitarized zone."
But Howard Prince, a young Army officer fighting at Hue, said Westmoreland had it backwards. Khe Sanh was the diversion.
"Westmoreland and his staff, the people who were advising him, became fixated on Khe Sanh," says Prince, "to the point where they simply were not capable of entertaining other information."
Others were willing to entertain the importance of the Tet Offensive. Among them was Walter Cronkite, the CBS anchor who arrived in Hue and quickly realized he'd been deceived by his official sources back in Washington.
What Cronkite saw on the ground led him to go on TV and say it was time for the U.S. to end the war.
"The only rational way out then," Cronkite said to a national audience, "will be to negotiate not as victims but as an honorable people who lived up to their pledge to defend democracy and did the best they could.
Johnson is said to have told an aide, "If I've lost Cronkite, I've lost middle America."
And maybe more than that. Bowden says Tet spurred not just a lack of trust about Vietnam policy, but a more general disregard for government officials that continues to this day.
"On the heels of Hue," says Bowden, "on the heels of Tet then came the Pentagon Papers, came the Watergate break-in, a series of kind of catastrophic events in terms of the public's perception of its own leaders."
A month after the Tet Offensive Johnson went on TV and said he would press for peace, stop the bombing in North Vietnam. Then he dropped his own bombshell: He would not seek another term as president.
Howard Prince watched it from his hospital bed in Texas, recovering from wounds he suffered at Hue.
"I was ready to throw a bed pan at the television set," he recalls, "because to me what that was was an admission of defeat and a denial of the sacrifice that all those young men had made and that I had made."
The Tet Offensive was an American military victory, says Prince. And Johnson should have taken the fight to North Vietnam and gone after the enemy's safe havens in Laos and Cambodia.
"We're doing the same thing today with the Taliban in Afghanistan," Prince says. "We're allowing you to run over into the borderlands in Pakistan and do the same thing."
Bowden agrees that even today, there are military parallels to the Vietnam War.
"We often find ourselves mired in situations where we don't have the cultural understanding, we don't have the historical understanding," Bowden says. "We can't gain the support of the people whether it's in Iraq or Afghanistan, and it stems from a kind of an arrogance and a general ignorance."
For his part, Mark Downs, another young Marine officer, will only say he and his men did their best.
This week Downs will remember those from Fox Company who were killed or wounded. Their names are carefully written in a small notebook he carried during those days a half century ago. And he begins to read the names.
"The killed were, I think he was a PFC, Stanley Murdock. D.I. Collins. A corpsman by the name of Gosselin, Doc Gooslin. Cristobal Figueroa-Perez."
Copyright 2018 NPR. To see more, visit http://www.npr.org/.