Henry Kissinger's contribution to the current flood tide of remembrance of the Vietnam War would be noteworthy simply because no other policymaker (presidents included) had more influence on the outcome over a longer span. It is all the more so because he works his way within easy reach of one clear lesson of the Vietnam experience. It has to do with free expression, public trust and the imperative for effectively mobilizing some degree of congressional support.

And yet he still can't get a grasp of it.

Leave aside his analysis of how the war itself went wrong: a flawed strategy of attrition and gradual escalation unsuited to guerrilla warfare; a traditional American inability to understand why you can't bomb and talk at the same time; a collapse of public support beginning with "fringe" groups seeking "radical transformations of society"; a divisive Congress carrying dissent to excess; the ravages of Watergate; and, of course, the media.

Leave aside, as well, no more than you'd expect in the way of scapegoating, self-serving and selective recall. The rule holds for statesmen defending their own failed ventures: Being involved means not having to say you're sorry.

On the contrary, as with Richard Nixon in his latest book ("No More Vietnams") so it was with Kissinger in his recent syndicated column. Both insist Vietnam could have been brought off with success and honor and that, indeed, it was with the signing of the Paris peace accords in January 1973.

But the "rewards and penalties so painfully assembled" to enforce the accords were "systematically dismantled" when a distrustful and irresolute Congress, in June of that same year, prohibited resumption of U.S. military action "in, over or near" Indochina and slashed aid to South Vietnam.

Kissinger fails to remind us that those peace accords hung together on a secret "side letter" from Nixon to South Vietnamese President Nguyen Van Thieu promising swift American reentry into the fray if the North Vietnamese broke the truce. This was a promise Nixon could not have hoped to deliver on, given the state of the congressional revolt.

Kissinger says simply, "The United States owed the peoples of Indochina a decent opportunity for survival; its domestic divisions made it impossible for the United States to pay this debt."

Now that may be the case by the time Nixon and Kissinger took charge (depending on how you define "decent"). But what are the lessons? Kissinger starts out sensibly. Prevention is the best cure for guerrilla war, meaning generous programs of assistance and reform. Failing preemption, American combat troops should not be committed without a "clear understanding of the nature of the threat and of realistic objectives" -- after which there can be no alternative to achieving those objectives.

Finally, Kissinger insists that "a democracy cannot conduct a serious policy if the contending factions do not exercise some restraint in their debate." That's where the reach exceeds the grasp: Where do you draw the restraining line and who draws it -- Congress or the executive?

The only answer I can think of is that both parties, by their own behavior, must practice and thus encourage restraint.

Kissinger gives no answer. But a hint to his thinking about where the responsibility lies is found in the "vaunted credibility gap."

He says the gap was a media creation, easily constructed by harping on the "differences between governmental statements and what in fact happened." He goes on: "A fairer analysis would have sought to determine what was due to genuine confusion and what was actual misrepresentation."

He's got it all backward. The confusion was not the government's but that of the public and Congress -- born of the government's misrepresentations. They are too plentiful to bear recital -- misrepresentations all through the record about the mission of the first combat troops in Vietnam, about the numbers that would subsequently be needed, about the objective. I don't mean miscalculations; I'm talking about conscious deception. The Pentagon Papers include documents establishing artful dissembling as a matter of executive policy.

As for differences between statements and what happened, why should promises unmatched by performance not lead legitimately to a loss of credibility? How many lights, after all, were we shown at the end of how many tunnels? However honest the misjudgments, repeated progress reports that turn out to be empty are the natural breeding ground of the distrust and domestic division Kissinger so deeply deplores.

Given the problem of conducting a war "amid such passions by himself," Kissinger argues, "Nixon should have gone to Congress early in his term, outlined his strategy and demanded an endorsement. Failing that, he should have liquidated the war." But Nixon rejected that advice, fearing that history would "never forgive the appalling consequences" of such an "abdication of executive responsibility." Kissinger still thinks that was "an honorable, highly moral decision."

Yet he also seems to think it was the wrong decision, which only goes to show -- with Lebanon and Nicaragua as examples close at hand -- that Kissinger is right on one point. "If Vietnam is to leave any useful legacy, America owes it to itself to make a fair assessment of the lessons of that tragedy," he writes, adding: "That has not yet occurred."