Three years ago, in the anxious days before America invaded Iraq, I found myself thinking back to 1949. Literally speaking, I could not possibly remember that time, having been born only in 1955. Yet from my reading of history, and in particular one book, I had the palpable sense that my nation had arrived at a comparable crossroads of decision. In the first stage of the Cold War, as the World War II alliance between the United States and the Soviet Union was devolving into global rivalry, the historian Arthur Schlesinger, Jr. wrote a manifesto pointedly titled The Vital Center. He espoused a middle ground that was anything but equivocal, one capable of fiercely resisting both the left wing's na ve idealism about communism and the right's McCarthyite excesses. "If we believe in free society hard enough to keep fighting for it," Schlesinger wrote, "we are pledged to a permanent crisis which will test the moral, political and very possibly the military strength of each side." At another point, in words that would prove prophetic decades later, he declared, "Terror is the essence of totalitarianism; and normal man, in the long run, instinctively organizes himself against terror." In the first weeks of March 2003, I read Schlesinger's words as a call to support the armed overthrow of Saddam Hussein. No matter that President Bush, leader of the effort, was a disaster on virtually all other issues, domestic or foreign. No matter that Schlesinger himself opposed the war. I still perceived liberal hawks like myself - Paul Berman, George Packer, Christopher Hitchens, Thomas Friedman - as the logical successors to the anti-communist liberals of Schlesinger's time, among them Eleanor Roosevelt and Reinhold Neibuhr. THE STAKES in Iraq only began with Hussein's flouting of United Nations weapons inspectors and his documented atrocities against Shi'ites and Kurds. The broader issue was the concept of idealistic intervention, the application of force of arms to halt mass murder and install democracy. The 1990s had seen the principle effectively enacted against Serbs in the Balkans and criminally unused in Rwanda, at the cost of 800,000 Tutsi lives. The world had something to gain, it seemed to me back in 2003, if the internationalist wings of both the Democratic and Republican parties could agree that American power had a purpose besides either imperial ambition on the one hand or isolationist self-defense on the other. Now, on the third anniversary of the invasion, I confess to feeling like a sap. This conclusion comes from no unique insights or experiences. I have not seen the war firsthand; I have not interviewed the policy-makers and strategists. As a relatively informed citizen, however, I have absorbed too many reliable reports to view Iraq as anything but a fiasco. I will never agree with early critics of the war that the invasion amounted to a kind of original sin. I do not believe it was at all unreasonable to assume Hussein was hiding weapons of mass destruction from UN inspectors, as he had before the first Gulf War in 1991 and as experts in the Clinton administration believed into 2000. I argue against the Vietnam War analogy, because fighting against a tyrant with a track record of mass murder cannot honestly be compared to fighting against a genuinely nationalist movement, no matter how infused with Marxism. There is a reason why the American weariness of this war has not been accompanied by massive peace marches, as was the case during Vietnam. The possibility that Iraq could have been liberated into freedom instead of anarchy, popular government instead of civil wars, makes the bungled occupation a tragedy with both immediate and long-term consequences. Here and now, Iraq has been turned into exactly what President Bush claimed that America needed to stop it from becoming - a forward base of Islamic terrorism. And because the result has been so utterly counterproductive, so wasteful of life and political will, the specter of Iraq is bound to hang over the concept of idealistic intervention for decades to come, turning that phrase from a trumpet call to action into a ringing alarm against repeating the mistake. JOURNALISTS today and historians tomorrow will parse the blame for the Iraq debacle, weighing the effect of too few troops, prison atrocities, the decision to disband the defeated Iraqi army, the failure to provide security and restore public services. Regardless of how one works the equation, the answer remains the same. The United States cannot stay, and it cannot leave. It bleeds to death in place, or bequeaths a fertile home to the international jihad. Those of us old enough to recall the Vietnam years can still summon up memories of the night Walter Cronkite told his nationwide news audience the war could never be won. Even the president, Lyndon Johnson, knew Cronkite was serving as the vox populi. In an era of 400 cable channels and the infinite clamor of the Internet, no single voice can match Cronkite's authority, which may be one reason the Bush administration still trots out the old trick of blaming the media for focusing only on the bad news. None of the defenders and apologists had much of an answer a few months ago, though, when Congressman James Murtha addressed the issue. He is a conservative Democrat, a decorated Vietnam veteran, a one-time supporter of the Iraq invasion. One need not agree with his proposed remedy of immediate withdrawal to recognize the sad accuracy of his diagnosis: "The war in Iraq is not going as advertised. It is a flawed policy wrapped in illusion. The American public is way ahead of us. The United States and coalition troops have done all they can in Iraq, but it is time for a change in direction. Our military is suffering. The future of our country is at risk." Such is the sound of the center, more violated than vital. The writer is a professor of journalism at Columbia University. His most recent book is Letters to a Young Journalist.