MR. CAVETT: No one has said that there’ll be a bloodbath if we pull out, which is a cliche we used to hear a lot. Does either of you still think there would be a –

MR. O’NEILL: I think if we pull out prematurely before a viable South Vietnamese government is established, that the record of the North Vietnamese in the past and the record of the Viet Cong in the area I served in…clearly indicates that’s precisely what would happen in that country.

MR. CAVETT: That’s a guess, of course.

MR. KERRY: I –

MR. O’NEILL: I’d say that their record at Hue, at Daq Son, at a lot of other places, pretty clearly indicate that’s precisely what would happen. Obviously, in Hue, we’ve discovered, how many, 5,700 graves so far, at Daq Son four or five hundred.

MR. KERRY: The true fact of the matter is, Dick, that there’s absolutely no guarantee that there would be a bloodbath. There’s no guarantee that there wouldn’t. One has to, obviously, conjecture on this. However, I think the arguments clearly indicate that there probably wouldn’t be.

* * *

That exchange is from the now-famous debate between the young John Kerry, leader of Vietnam Veterans Against the War, and another veteran of the riverine war in the Mekong Delta, John O’Neill, now a leading figure in the Swiftboat Veterans for Truth. The entire debate is accessible online, in a video, and the transcript quoted above, at swiftvets.com. We watched it again yesterday, after a week in which Senator Kerry finally made his morph – long predicted here – into the anti-war candidate Americans have, deep down in their hearts, known him to be all along.

The broadcast is one of the most illuminating we’ve watched in years. Mr. Cavett was a fair and shrewd host. The future senator spoke in a more pronounced Brahmin accent than he has today and with a slickness that prefigured his political career. John O’Neill, an Annapolis graduate who served three full years in Vietnam, evinced a nerdy earnestness in the face of an audience that clearly seemed to be in Mr. Kerry’s corner. If it were Hollywood, Mr. O’Neill would have been played by Jimmy Stewart.

It was the substance that is devastating, the more so when viewed with the advantage of hindsight. Mr. Kerry pressed his line about ending the war immediately, without taking the time or risking soldiers’ lives to protect the emerging government in free South Vietnam. It was a follow-on to his notorious question, “How to you ask a man to be the last man to die for a mistake?” He was confident the prisoners being held in Hanoi would be released, bringing a sharp riposte from Mr.O’Neill that no one had accounted for prisoners being held by the Viet Cong and in Laos.

There was an extraordinary passage in which Mr. Kerry tried to blame the Americans for the deaths of the mountain populations resisting the communists – the Montagnards and the Meo – only to be reminded brusquely by Mr. O’Neill that these heroic tribes were on our side. And they remained heroically loyal to our side and our ideals, even after the communist conquest, which is why the communists tried to drive them out of the highlands of two countries, going so far, in Laos, as to use poison gas.

Mr. Kerry mocked the American administration, then led by President Nixon, for its commitment to a solution that would allow a noncommunist regime in the South, despite the fact that by then world history was littered with the corpses of regimes that thought they could include communists in a coalition. One doesn’t have to accuse Mr. Kerry of being a pro-communist agitator to suggest that to the danger of a communist conquest he was appallingly indifferent. He wanted what Hanoi wanted, which was to get the Americans out immediately.

Let it never be forgotten – now more than ever – that a bloodbath did follow the American abandonment of Vietnam, just as Mr. O’Neill and many others warned that it would. Hundreds of thousands were thrown into re-education camps in Vietnam, many tens of thousands, or more, to perish there. And hundreds of thousands, or millions, fled, risking their lives in small boats to escape the totalitarian system that was imposed once Congress took the advice of Mr. Kerry and his cohorts and abandoned the fight. The bloodbath in Vietnam paled only in comparison to Cambodia, which was even worse; millions met their deaths in the killing fields where the Red Chinese backed-Khmer Rouge held sway.

Surely the anger against Mr. Kerry on the part of the Swiftboat veterans, who are out with a stunning new advertisement this month, derives not only from his slur on their honor but his indifference to the fate of the Vietnamese, Cambodians, and Laotians we went there to help. In the light of history it is clear that Mr. Kerry made the right decision to go to Vietnam and the wrong one to abandon the fight and turn against the war. He’s making the same error now in coming out against the war in Iraq. To understand why, the place to look is the very bloodbath that Mr. Kerry so blithely assured was unlikely in Indochina.