The Tet Offensive shocked the nation and permanently changed US attitudes toward the Vietnam War

The Tet Offensive, a surprise attack launched by North Vietnam in the pre-dawn hours of Jan. 31, 1968, was a major turning point in the war. It shocked the American public into reality about the escalating conflict and led to President Johnson’s decision not to seek re-election.

What exactly had happened and what it meant took some time to sort out. All that was clear at the time was that something startling had occurred and that the US was up against a much more formidable opponent than most Americans had previously believed.

“The shock of Tet was just enormous,” says Barry Zorthian, who was in charge of press relations for the US Military Command in Saigon. “That front page of The Washington Post in the morning, with the pictures of the American Embassy — the symbol of everything, not destroyed, but pretty well damaged — and dead people all around — that had to be one of the great, great shocks and traumatic events in Washington.”

Sam Adams, a CIA analyst who was stationed in Vietnam at the time, believes Hanoi’s chief objective was to “jolt American public opinion right before the American elections. And in my view they succeeded in spades in doing that.”

The Tet offensive also had a great impact within Johnson’s administration.

Secretary of Defense Robert McNamara told Johnson: “I think it shows two things, Mr. President. First, that they have more power than some credit them with. … My guess is that we will inflict very heavy losses on them, both in terms of personnel and matériel and this will set them back some, but after they absorb the losses, they will remain a substantial force. I don't anticipate that we will hit them so hard that they'll be knocked out.”

Listen to McNamara's report to Johnson and Johnson's response. 

Like Adams, McNamara saw the Tet Offensive as primarily a propaganda effort and this assessment proved to be accurate. In military terms, the Tet Offensive was a defeat for the North. Politically, however, it was a public relations disaster for the president.

For the first time, it became clear to the American public that the White House had either underestimated the strength and resolve of the North or, more damagingly, knew the truth but kept it from them. Either way, the president's credibility on the war took a hit from which he would never recover.

In typical fashion, Johnson lashed out at the press, telling a reporter that the “press is lying like drunken sailors every day. … How can we possibly win and survive as a nation and have to fight the press’s lies? … I don't admit that this is a Communist victory. And I don't think anybody but a goddamn communist admits it.”

Barry Zorthian believes LBJ never felt he had the confidence of the American public. As a result, he conducted the war in a way that provided as little information as possible, which only increased the shock of Tet.

“The American people were never involved,” Zortheon says. “They were told to go about their normal, prosperous lives while we were fighting this nasty little war in Asia. Suddenly, you turn around and we've got a half million people out there and more on the way. No limit to it. And the story broke that Westmorland wanted 200,000 more troops. We were going to hit 700,000. And that's what I think Walter Cronkite reacted to, in part. That feeling of just the quagmire, that there was no end to it.”

In mid-February, the venerable CBS News anchorman Walter Cronkite went to Vietnam to make his own assessment of the impact of the Tet Offensive. Upon his return, "the most trusted man in America,” as he was then called, had a grim report for the nation.

“To say that we are mired in stalemate seems the only realistic, if unsatisfactory, conclusion,” he said on his broadcast. “On the off chance that military and political analysts are right, in the next few months we must test the enemy's intentions, in case this is indeed his last big gasp before negotiations. But it is increasingly clear to this reporter that the only rational way out then 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 had tried repeatedly to initiate talks toward a settlement of the war — which he believed in sincerely — but they had all been ignored or rebuffed. By the time of the Tet Offensive, the president had concluded that only sustained bombing and a stepped-up ground war could get the North Vietnamese to the conference table.

McNamara, who had privately admitted to doubts about the war, had already announced his resignation in late 1967 and departed in February 1968 to head the World Bank. McGeorge Bundy, also an advocate for standing firm in Vietnam in the early days, had likewise had a change of heart and left the White House. Of the original war council, only Dean Rusk remained inside as his embattled and increasingly isolated president circled the wagons.

In January, LBJ had appointed Washington insider Clark Clifford, a longtime supporter of the war, to replace Robert McNamara as secretary of defense.

“When I came into the Pentagon job on March 1, 1968, that’s when all of the concerns that I might have felt before all began to come to the surface,” Clifford said in an interview. “I’d push them down here and they’d pop up there, and I’d go home at night and be uneasy and disturbed and then we'd start again the next day and we’d grind through this business.”

Clifford finally put the matter to the Joint Chiefs directly and came away dismayed by their response.

“I wanted to know, what is the military plan for victory in Vietnam? There was no military plan,” Clifford said. “The Joint Chiefs said, ‘What we must do is just continue to carry on as we are, and we believe that the attrition ultimately will become unbearable from the enemy’s standpoint.’ So, I say, ‘How long?’ ‘We don’t know.’ ‘Six months?’ ‘Oh, no, it can’t be done in that period.’ ‘A year? ‘Well, no.’ ‘Two years, three years, four years?' Well, nobody knows. Here's this kind of bottomless pit. We could just be there year after year after year, sacrificing 10,000 American boys a year, and it just didn't add up.”

For four-and-a-half years, LBJ had waged war and sought peace in Vietnam, without success on either score. The Tet Offensive had brought the terrible reality of the war home to an electorate that, for the most part, had not until then fully reckoned with its costs and consequences.

On March 31, 1968, eight weeks after the shock of Tet, Lyndon Johnson, in a reckoning of his own, administered an aftershock.

“Accordingly, I shall not seek and I will not accept the nomination of my party for another term as your president,” Johnson told the nation.

John Chancellor, who covered the White House for NBC News and would later anchor its nightly broadcast for a dozen years, believes Johnson “would not have been forced into the unhappy decision not to run again if the country had been better prepared, if the country had understood what he was doing in Vietnam.”

“The one great disadvantage Lyndon Johnson had in running this country is that the people didn't quite trust him,” Chancellor says. “That sense of uneasiness and mistrust can kill a president, and it did Lyndon Johnson.”

This article is based on the PRI podcast, LBJ's War, hosted by David Brown.