IN 1971, WASHINGTON was shocked when a throng of battle-scarred veterans showed up to protest the war in Vietnam. They camped on the Mall, and the Nixon administration quickly obtained a ruling from Chief Justice Warren Burger ordering the veterans to clear out.

They refused. Would they be arrested? It was then that Senator Edward M. Kennedy boldly went to the Mall where the antiwar veterans had pitched their tents and sleeping bags. ''You have served your country well abroad,'' he told them, ''and will serve it even better here in Washington.''

Kennedy's public support of the illegal demonstrators was key in turning the tide of opinion - and then law - in the veterans' favor, and a crucial blow against the war was struck (See ''Home to War'' by Gerald Nicosia).

Ted Kennedy is doing it again. ''I started my career at a time when there was a war that was important to end,'' he said to me as we sat together last Saturday. ''And now - not that I am finishing my career - there is a war that requires us to relearn those lessons of history.''

A few minutes later, in Harvard's Sanders Theater, Kennedy delivered a stirring address at the induction ceremony of the American Academy of Arts and Sciences, perhaps the strongest criticism of the move toward war in Iraq yet made by a leading politician, although you would not know that from the way the speech was ignored in the drum-beating media.

Instead of focusing on the details of the prowar resolution that Congress will likely approve this week, Kennedy hom ed in on ''a more fundamental debate that is only just beginning - an all-important debate about how, when, and where in the years ahead our country will use its unsurpassed military might.'' Iraq is simply the first case in point.

Responding to the Bush administration's recently published ''National Security Strategy of the United States,'' Kennedy carefully dissected the radical assumptions that are driving the nation toward war. First, he showed that by equating the two quite distinct purposes of ''prevention'' and ''preemption,'' President Bush is leading America to embrace a course of action it has long condemned in others.

''Traditionally,'' Kennedy said, ''`preemptive' action refers to times when states react to an imminent threat of attack.'' He offered Israel's response to the border-moves of Egypt and Syria in 1967 as an example of justified preemption. By contrast, the Japanese attack on Pearl Harbor, intending to undercut a potential ''capability that could someday become threatening,'' was a ''preventive'' action. ''The coldly premeditated nature of preventive attacks and preventive wars makes them anathema to well-established principles against aggression.''

To Kennedy, preventive war is still anathema, and his denunciation of the Bush embrace of preventive war against Iraq draws its edge from the fact that President John Kennedy, in 1961 and 1962, rejected the argument for preventive war against the Soviet Union, protecting a moral boundary. ''For 175 years,'' Edward Kennedy quotes Robert Kennedy as saying, ''we have not been that kind of country.''

Are we now? The Bush administration's new doctrine, Kennedy said, ''asserts that global realities now legitimize preventive war and make it a strategic necessity. The document openly contemplates preventive attacks against groups or states, even absent the threat of imminent attack I strongly oppose any such extreme doctrine.''

The second feature of Bush's radical new approach that Kennedy lambasted was its assumption that the United States is somehow exempt ''from the rules we expect others to obey.'' Kennedy reiterated an old cliche of public morality - ''Might does not make right!'' - but in the present context, his reference rang with prophetic relevance. The hubris of overwhelming power is corrupting the nation. ''America cannot write its own rules for the modern world. To attempt to do so would be unilateralism run amok.'' Bush is undercutting the war on terrorism, destroying alliances, setting dangerous precedents, and eviscerating America's moral legitimacy.

Again daring to go where few of his colleagues venture, Kennedy defined all of this by its proper name: ''The administration's doctrine is a call for 21st century American imperialism that no other nation can or should accept.'' The debate in Congress this week is centered on Saddam Hussein and Iraq, but what is really at stake are basic structures of the American idea. The name Kennedy is properly attached to this nation's noblest impulse, and it is fitting that the last of the brothers is raising his voice in its defense.

The afternoon of his speech, the senator and I were sitting in a Somerville cafe. A customer approached our rear-corner table to say, ''Senator, I want to thank you for all you're doing to stand up for us against this rush to war.''

I asked her name, and if I could quote her. ''Lucy Borodkin,'' she said firmly. ''And you certainly can.''

James Carroll's column appears regularly in the Globe.

© Copyright 2002 Globe Newspaper Company

###