Our fractious foreign policy debate.

THREE decades after the Vietnam War, American politicians are still making foreign policy decisions in its shadow. In fact, on one level, debates such as those over the recent war in Iraq can be viewed as hinging on how one interprets the American experience in Vietnam. Was that war merely a case of overreach or was it the typical case--that is, was it what happens whenever the United States undertakes military interventions more dangerous and open-ended than, say, Grenada?

The debate about the lessons of Vietnam is largely, but by no means simply, identical to the Left-Right divide. The cautionary Summers Doctrine, which dominated American military strategy for so many years and was influential among many conservative policy makers, is unmistakably an answer to the question of how America erred and what to do about it. With its insistence on limited aims, exit strategies, and strong public support, it essentially argued that only if there is no chance of "another Vietnam" should we get involved. At the same time, confusion still reigns: Some of the chief liberal opponents of the Vietnam War, like Anthony Lewis, were passionate advocates of Balkan interventions that some conservatives opposed as potential quagmires.

In truth, the debate over the Vietnam War was never really resolved. This was readily evident when the first Gulf War was approved by only a single vote in the Senate. Here the war aims were limited; the cause--defense of a small nation conquered by a ruthless neighbor--easy to justify; the real stakes--Gulf oil and its concomitant blackmail rights in the hands of a ruthless despot--high; and the military superiority of the coalition overwhelming. Yet fears of another Vietnam made Senate approval a cliffhanger. Similarly, President Bill Clinton's lengthy hesitations in the 1990s over what to do about the Balkans reflected the moral uncertainty of the country as a whole. Even the 1989 Panama invasion, trivial as it may appear in retrospect, gave rise to enough agonizing reappraisals that the British journalist Henry Fairlie marveled at how Americans have to refer back to fundamental principles to justify even the smallest of foreign interventions.

This particular strand in our politics is directly attributable to what, for lack of a better label, I will call the "Vietnam paradigm." It describes not simply a constellation of isolationist policy directives but, more importantly, a general attitude of political suspicion and moral condemnation of nearly any use of American military might. Such post- Vietnam skittishness has affected America's domestic politics in enormous and largely pernicious ways. Most significantly, it has made popular consent for any large-scale foreign intervention--and thus the credibility of any such threat--perennially fragile. This has led conservatives when in power to fight wars on tiptoe. They tend to counter dogmatic pessimism with a forced and precarious optimism. By cutting the margin of error too thin, they end up, paradoxically, strengthening the very fears their policies were meant to avert or placate.

The Vietnam paradigm has become an article of faith for large parts of public, and especially elite, opinion. But it is the paradigm's peculiar underpinnings, almost theological in nature, as I shall argue, that have created a ratchet effect in the level of venom in policy debates domestically. Ultimately, the basic terms of political discourse necessary for the flourishing of liberal democracy are put in jeopardy. This effect is intensified when, as now, the Vietnam paradigm is countered not just by apparently hardheaded defenders of national interest but by a counter-moralism or idealism. The latter offers not simply an alternative policy but threatens the very self-understanding of those who typically see any American intervention as immoral. Furthermore, the way of thinking about politics that sustains the Vietnam paradigm or mindset is in some ways a natural result of the apolitical character of most American life. Opponents of this way of thinking face an extraordinarily difficult task. Not only must they rebut the policy recommendations of its advocates ("America come home"), but they must also overcome the politics of indignation--a political worldview that puts the highest value on knowing its own moral righteousness--that undergirds them. They must pursue tactical policy ends while engaging in a long-term process of public education that has as its end the preservation of our liberal-democratic order.