Indeed, the similarities in the run-up to the Vietnam and Iraq wars are striking. In the prelude to the Bush Administration's 2003 decision to invade Iraq, there was no figure immediately comparable to George Kennan, or to McCarthy. Yet we witnessed a similar institutional failure as neoconservatives seized the debate from the State Department, the CIA, the uniformed military, the think tanks and the academy. Some, like Middle East scholar Bernard Lewis, even reversed positions. Following White House meetings with the vice president, Lewis approved the war rationale: "Get on with it. Don't dither." Others advanced templates (like Samuel Huntington's "Clash of Civilizations") that exacerbated emotions, simplified the challenge and framed a process of confrontation-not-engagement.

Think tanks like Brookings, CSIS, Heritage, AEI and most notably the Council on Foreign Relations were silent. Search the archives of CFR's Foreign Affairs from Fall 2001 to Spring 2003, and you'll find numerous articles making the case for war-and plenty of pro-war books reviewed-but no skepticism about the looming decisions on Iraq.

Just as Fulbright and the anti-war movement combined with events in Vietnam to facilitate open dialogue, so Democratic presidential aspirant Howard Dean fractured Congress's reticence to challenge a "war" president. The Big Idea of the day, freedom on the march, was rooted in a strident linguistic code emanating directly from the White House. Following the 9/11 attacks, then-White House Press Secretary Ari Fleischer scolded journalist Bill Maher for asking if the word "cowardly" accurately described suicide bombers: "It's a terrible thing to say . . . [They're reminders] to all Americans that they need to watch what they say, watch what they do. This is not a time for remarks like that; there never is." These were no longer "normal times." With freedom under attack, dissent gave aid to the enemy, just as it had during the McCarthy years.

Writing in 1961, Kennan foreshadowed post-9/11 America: "There is nothing more egocentrical than the embattled democracy." Under such circumstances, he argued, a democracy will attach to its cause "an absolute value that distorts its own vision of all else." Important questions go unasked, unchecked assumptions harden into common knowledge and the mission assumes a "final apocalyptic quality." The public and leaders alike come to think that, as Kennan wrote,

if we lose, all is lost and life will no longer be worth living; there will be nothing to be salvaged, but if we win, then everything will be possible; all our problems will be soluble; the one great source of evil, our enemy, will have been crushed; the forces of good will then sweep forward unimpeded, all worthy aspirations will be satisfied.

Saddam Hussein was that great source of evil. Take him down, neoconservatives argued, and democracy will blossom not only in Iraq, but throughout the Middle East. But Kennan, of course, wasn't talking about Iraq. He was disillusioned with how his thesis of the 1940s-a sophisticated understanding of international communism-had been transformed into a one-word slogan to justify policies he opposed.

Dean Acheson, Truman's secretary of state, thought sophisticated analyses like Kennan's unsuitable for the 1950s. It was better not to risk arguments that were "unpalatable to believers in American omnipotence." The challenge, said Acheson, was to "so bludgeon the mass mind. . . that not only could the President make a decision, but that the decision could be carried out." Also: "The task of a public officer who is seeking to explain and gain support for a major policy is not that of the writer of a doctoral thesis. Qualification must give way to simplicity of statement, nicety and nuance to bluntness."

The mass media is McCarthy's 21^st-century equivalent. It has been vital in structuring and formatting the information shaping the public discourse. Administration-manufactured crisis narratives feed the media's hunger for sensation and drama. Ratings-driven media competition exploits an insecure public's compulsion to learn as much about crises as quickly as possible.

Given the confluence of powerful media and political interests, how does one break the cycle-how can the expert community distill the cacophony of competing agendas to provide accurate assessments? In fact there has been a return to rationality, but it has not been led by the rational center. It has been made possible by the failure of neoconservatism.

Just as reality was a harsh teacher in Vietnam, so it is in Iraq. As Big Ideas like "The Domino Theory" and "Freedom on the March" publicly and dramatically fail, the rational center replaces them with realism. A return to balance is not surprising; it happened after McCarthy and after Vietnam as well. What is noteworthy, however, is that this syndrome repeats itself.

Twice in the last half-century China has excited American passions, leading Washington to adopt ineffective policy responses. Today, China challenges the United States for energy resources, trade relationships and geo-political influence throughout the developing world. Moreover, holding some $350 billion of U.S. debt, China can change the value of the dollar. In a confrontation with China, unlike with Iraq or Venezuela, there is no room for error.

Should patriotic passion and Big Ideas frame China policy, we will again experience institutional failure, the marginalization of experts and dysfunctional policy. We must avoid this. The results could profoundly alter American life.

Stefan Halper is a senior fellow at the Centre of International Studies at the University of Cambridge, where he directs the Atlantic Studies Programme. He served in the Nixon, Ford and Reagan Administrations. He is co-author of The Silence of the Rational Center: Why American Foreign Policy is Failing(Basic Books, 2007).