Events this week in both the United States and Iraq have been marking the impending end—with the withdrawal by the end of this month of the last U.S. combat troops from Iraq—of a miserable chapter in American history, one that did not have to happen and should not have happened. President Obama has struck the appropriate notes for a commander in chief, giving primary attention to recognizing the sacrifices of those Americans—more than 1.5 million of them, as the president observed—who have served in Iraq during these past nine years. Having been clearly opposed to launching this misadventure, Mr. Obama had every right to say “I told you so” but refrained from any remark that came close to that. Besides recognizing the contributions and sacrifices of U.S. troops, he has, including in his appearances with Iraqi prime minister Maliki, looked to future issues of U.S.-Iraqi relations rather than dwelling on mistakes of the past.

The rest of us, unencumbered by a commander in chief's responsibility to maintain the respectful and reassuring tone that the president maintained, should do plenty of dwelling. We should think and talk, long and hard, about how and why the United States could ever have committed such a huge mistake. We need to do so to reduce the chance of comparable disasters in the future.

The Iraq War has not been the costliest war the United States has ever fought, but when taking into account the how and why of getting into it in the first place, the Iraq War ranks as one of the greatest blunders in American history and one of the biggest travesties in the relations of the United States with the rest of the world. The war was the project of a small, mostly neoconservative cabal that wanted to use Iraq as an experiment to inject democracy and free enterprise into the Middle East through the barrel of a gun. The cabal got much of the rest of the country to go along with their scheme by exploiting national anger and anguish over the 9/11 terrorist attack and by conjuring up scary tales of dictators giving weapons of mass destruction to terrorists.

A ledger on the war assembled by the Center for American Progress summarizes some of the huge costs. There are, first and foremost of course, the nearly 4,500 members of the U.S. military who have made the ultimate sacrifice. That's about one and a half times the death toll of 9/11, the terrorist event that the promoters of the war repeatedly linked with Iraq in order to sell their project. Over 32,000 Americans were wounded—many of them grievously maimed from combat that in earlier wars, when today's body armor was not used, would have killed them. Among Iraqis—the people whom we were supposedly rescuing from a savage dictator—over 100,000 civilians have been killed, and more than 2.8 million have been driven from their homes as either refugees or internally displaced persons. And the bloodshed and civil strife in Iraq are far from over.

The direct monetary cost to the United States of Operation Iraqi Freedom has been over $800 billion. Projections cited in the CAP report of the total cost of health care and disability benefits for veterans of the Iraq War range from $422 billion to $717 billion. Add that to the direct cost of military operations and, by way of comparison, we are in the same range as the $1.4 trillion that the Congressional supercommittee was supposed to find in deficit reductions over ten years. There are in addition many other follow-on costs, from replacement of military equipment to indirect economic effects, that have led some economists to estimate the total cost of this war to be more like $3 trillion.

The political, diplomatic and strategic costs are not quantifiable but vast. The United States severely damaged its image and standing in the rest of the world, especially in predominantly Muslim countries, with everything such damage implies in terms of getting or not getting cooperation in pursuit of U.S. interests. The war has boosted extremist sentiment and ideology, hatred of the United States, and international terrorism that is fueled by both. It has increased the regional influence of Iran. Far from leading to a spread of democracy several years ago, it soured many Middle Easterners on the idea of transitioning to democracy. And the war has been a huge preoccupation and diversion, using up time, attention and diplomatic chits that otherwise could have been applied to other U.S. interests.

Learning from this blunder does not simply mean not using force overseas rather than using it. There may be an Iraq syndrome that echoes the Vietnam syndrome of an earlier generation, but just accepting that would be a crude response and not necessarily the best lesson. We need to reflect on the specific attributes of this experience—involving the decision to go to war at least as much as the war itself—that made it so pathological.

One of those attributes is that the United States launched a war of aggression. That is a major break with American tradition. The Iraq War was the first major offensive war that the United States waged in more than a century—since the war against Spain in 1898. All the other major wars that the United States had been involved in since then were responses to someone else's aggression. America lost some part of its principles and its character when its forces started rolling across the border into Iraq. It will take a long time to make sure we have those principles back.

Future historians will regard as one of the most extraordinary aspects of this war that there was no policy process to examine whether it was a good idea. There were no meetings in the White House with that question on the agenda, no policy-options paper—nothing. When asked a couple of years ago to contribute to a volume on lessons to be drawn from the Iraq War, I identified as the number one lesson the need to have a policy process before undertaking major policy initiatives, and certainly before something as major as starting a new war.

Closely related to the previous pathology was the grossly inadequate attention to what would happen once Saddam Hussein was toppled. It was an inadequacy exhibited not only by policy makers but also by the larger public discourse about Iraq. Americans, mesmerized by the war makers' chant about dire things that would happen if the Iraqi dictator were not removed, scarcely thought about what would happen once he was removed. An important lesson is that costly unintended consequences almost always result from a major undertaking such as a foreign war.

And related to that was the larger pattern of how many Americans allowed themselves to be duped by the war makers. That's right: allowed themselves to be duped. There have been many complaints by people who supported the war about how they were misled, and indeed Americans were misled. But they were able to be misled because they got themselves swept up in a political mood that was stoked and exploited by the administration. Even a halfway careful examination of the prowar sales campaign could have seen through it, including such things as a phantasmagorical alliance between the Iraqi regime and al-Qaeda.

Finally there are the prime promoters of the war. The lesson to be drawn about them is how atrocious the war showed their judgment to be. They ought to be so discredited by now that no one listens to them any more. But here's the scary part: people do still listen to them. As Christopher Preble observes, “Most of the president’s Republican challengers are reluctant to cross the neoconservative cheerleaders for the war who, inexplicably, still have great sway over aspiring chief executives.” Many of those cheerleaders are still prominent members of the policy-influencing Washington elite and still writing and talking about the very sorts of things on which they showed such terrible judgment in the case of Iraq. Some of them are even cheering for yet another war, against another Middle Eastern country with a four-letter name starting with I, and with their cheering featuring familiar old themes about weapons of mass destruction, links with terrorism and the like. Those people ought to be reminded at every turn about the Iraq War and their role in promoting it, and asked repeatedly why anyone should believe a word of what they are saying now.

Image: Joe Mabel