My youngest daughter was born in December 2001: a war baby. When my wife nursed little Beatrice in the middle of the night, she’d hear F-16s patrolling the Washington skies.

During the weeks before, anthrax attacks had killed five people and infected 17 others. What would come next?

In October, I attended a crowded briefing in the fourth-floor auditorium of the Executive Office Building, at which the Secret Service explained its plans to protect the White House against a biological attack. They weren’t very reassuring. Basically, we’d all be dead. Even more disturbing were the small-session briefings by staffers for the new Homeland Security adviser. They warned of simultaneous car bombings at strategic intersections, targeted assassinations of officials as they retrieved their morning papers from their stoops, and poisonous gases released in Metro stations.

Like many Washingtonians, my wife and I had prepared an emergency kit in the basement: canned goods, bottled water, flashlights, batteries. We had an evacuation plan, a rendezvous point two hours outside the city, and a stipulated wait time after which she was to presume I was a casualty.

These anxieties may sound luridly overdramatic today, but they suffused the mental atmosphere of the government of the United States as President Bush made the fateful decision to launch the Iraq War.

Yet it was not only fear that drove the administration’s thinking about Iraq. It was also passionate enthusiasm for a new Middle East.

The first time I met Ahmed Chalabi was a year or two before the war, in Christopher Hitchens’s apartment. Chalabi was seated regally at one end of Hitchens’s living room. A crowd of nervous, shuffling Iraqis crowded together at the opposite end. One by one, they humbly stepped forward to ask him questions or favors in Arabic, then respectfully stepped backward again. After the Iraqis departed, Chalabi rose from his chair and joined an engaged, open discussion of Iraq’s future democratic possibilities.

The last time I saw Chalabi was in his London apartment, on the very eve of war. My little group arrived past midnight. Chalabi was listening to the evocative strains of Sufi music. He showed me a black-and-white photograph of seven men, wearing the clothes of the 1940s. They were the board of directors of a company his father had founded: a mixed group of Sunni, Shiite, and Christian, and even a Jew. Chalabi remarked that this picture was taken while Europe was tearing itself apart in genocidal violence. He didn’t add that it was taken shortly after British forces defeated a pro-Axis coup in Baghdad—but failed to prevent a murderous pogrom against Baghdad’s Jewish population.

I was less impressed by Chalabi than were some others in the Bush administration. However, since one of those “others” was Vice President Cheney, it didn’t matter what I thought. In 2002, Chalabi joined the annual summer retreat of the American Enterprise Institute near Vail, Colorado. He and Cheney spent long hours together, contemplating the possibilities of a Western-oriented Iraq: an additional source of oil, an alternative to U.S. dependency on an unstable-looking Saudi Arabia.

You might imagine that an administration preparing for a war of choice would be gripped by self-questioning and hot debate. There was certainly plenty to discuss: unlike the 1991 Gulf War, there was no immediate crisis demanding a rapid response; unlike Vietnam, the U.S. entered the war fully aware that it was commencing a major commitment.

Yet that discussion never really happened, not the way that most people would have imagined anyway. For a long time, war with Iraq was discussed inside the Bush administration as something that would be decided at some point in the future; then, somewhere along the way, war with Iraq was discussed as something that had already been decided long ago in the past.

The order to begin work on the Iraq sections of the 2002 State of the Union address—what became known as the “axis of evil” speech—was delivered to me in the form of a conditional: what might the president say if he decided…etc. That speech provoked a furor with its claim that state sponsors of terror cooperated with terrorist groups, and its warning that Iraq, Iran, and North Korea were arming to threaten the peace of the world. Critics insisted that it was impossible that Shiite Iran would support Sunni Hamas or that Islamic Iran could share technology with Stalinist North Korea. We now know all those things to be true, and many more besides. The founder of the Pakistani nuclear program did attempt to sell bomb-making technology to al Qaeda. The North Koreans did sell Syria materials for a nuclear facility destroyed by the Israelis in 2007.

Some critics claim that the speech blew up a promising U.S. diplomatic overture to Iran. That’s pretty hard to believe, especially after seeing what has happened to U.S. overtures to Iran since 2009. As a description of the strategic challenge facing the United States, the speech has been corroborated by events. No apologies on any of those points.

The speech did mark a point of no return on the road to war with Iraq, although debate continued inside the administration for many more months. The famous Downing Street memo makes clear that as late as July 2002, Tony Blair’s government remained uncertain of U.S. intentions.

Mobilizing Congress and the American people in favor of Bush’s gradually emerging decision required a considerable messaging effort. Some in the administration had seized on early evidence that Saddam Hussein might be implicated in the 9/11 plot itself: Cheney was fascinated by a putative meeting in Prague between Mohamed Atta and Iraqi intelligence officers. That evidence rapidly unraveled—although I’m not sure that Cheney ever did agree that it had.

Undersecretary of Defense Paul Wolfowitz spoke eloquently about Saddam’s appalling crimes against the Iraqi people. But countries rarely fight big, expensive wars for the benefit of others. Everything depended on the evidence that Iraq was acquiring a dangerous arsenal of weapons of mass destruction. How solid was that evidence? Those of us without high security clearances could never truly know. We had to rely on those we trusted—like National Security Adviser Condoleezza Rice, who warned on January 10, 2003, “There will always be some uncertainty about how quickly Saddam can acquire nuclear weapons. But we don’t want the smoking gun to be a mushroom cloud.”

Such assurances by the leading figures in the Bush administration won the support of a broad array of Americans, not only conservatives but “liberal hawks” in Congress and the press, and not only in this country but around the world.

The Iraq War was not only an American war. Depending on how exactly you count, as many as 49 nations sent forces to Iraq. Poles fought in Iraq, and Koreans, and Danes, and Australians, and New Zealanders, and Spaniards, and Georgians. Canada sent trainers; Germany sent money. The largest allied contingent came of course from Britain, where the debate over the war raged even hotter than in the United States.

Blair, who had previously led his country into humanitarian military campaigns in Sierra Leone and Kosovo, laid more stress on the liberation of the Iraqi people and less on WMDs. Perhaps Blair’s version of the argument should have been heard as a warning that the WMD case was not as strong as the Bush administration made it out to be. At the time, though, Blair’s human-rights case for war reinforced the Bush administration’s national-security case.

Brits sometimes question how crucial Blair was in the run-up to war. My own sense, for what it’s worth, is that it was Blair, not Bush, who swayed Democrats in Congress and liberal hawks in the media. Without Blair, the Iraq War would have been authorized with only the smallest handful of non-Republican votes.

As it was, Bush adopted Blair’s arguments only in the last hours of the debate over the war, and then only very tentatively. Speaking to the American Enterprise Institute on February 26, 2002, Bush said: “The current Iraqi regime has shown the power of tyranny to spread discord and violence in the Middle East. A liberated Iraq can show the power of freedom to transform that vital region, by bringing hope and progress into the lives of millions. America’s interests in security and America’s belief in liberty both lead in the same direction: to a free and peaceful Iraq.”

The grand claims of a new democracy-based foreign policy only came later—after the discrediting of the national-security argument for war. It was in 2005, not 2002, that Bush declared: “It is the policy of the United States to seek and support the growth of democratic movements and institutions in every nation and culture, with the ultimate goal of ending tyranny in our world.”

By then, however, it was too late. The war had been planned as a lightning thrust: overthrow the dictator, destroy his weapons, then get out fast, leaving reconstruction to the Iraqis to run and the Europeans to pay for. By the time we’d shifted the basis for the war from WMDs to democracy, we were already committed to a strategy in which nation building was a distant afterthought.

Before the war, budget director Mitch Daniels drafted a paper showing that the Franklin Roosevelt administration had cut the civilian budget 25 percent to finance World War II. No such spending cuts would be forthcoming from the Bush administration. On the contrary, the administration enacted a costly new prescription-drug benefit in 2003. Nor would the administration rethink its tax cuts. Those decisions reflected a shrewd assessment of the political realities inside the congressional GOP. I used to joke that we’d someday see an all-out fight inside the GOP between those who said, “Your war wrecked our tax cut,” and those who said, “Your tax cut lost our war.” I was wrong: there was no fight. The tax-cut side of the party has utterly and effortlessly overwhelmed the war-fighting side.

In one of the darkest seasons of the war—probably about 2005, I don’t recall exactly—a Swiss journalist came to visit me. He excoriated me for more than half an hour about everything that had gone wrong in Iraq. He had been one of the leading voices inside his small country for the war. When things went bad, he had felt personally betrayed by those in America and Britain to whom he’d given his trust.

I think of that conversation often.

When Christopher Hitchens read in 2007 that Mark Daily, a young American killed in action in Iraq, had been moved by his arguments for the war, he summoned to mind the self-questioning verses of William Butler Yeats:

Did that play of mine send out

Certain men the English shot? …

Could my spoken words have checked

That whereby a house lay wrecked?

By 2007 it was clear that—whether the initial case for the war had been right or wrong—the management of the war had gone badly wrong. Hitchens, one of the most eloquent and honest of the war advocates, faced this truth forthrightly, as was his way: “Orwell thought that the Spanish Civil War was a just war, but he also came to understand that it was a dirty war, where a decent cause was hijacked by goons and thugs, and where betrayal and squalor negated the courage and sacrifice of those who fought on principle. As one who used to advocate strongly for the liberation of Iraq (perhaps more strongly than I knew), I have grown coarsened and sickened by the degeneration of the struggle: by the sordid news of corruption and brutality (Mark Daily told his father how dismayed he was by the failure of leadership at Abu Ghraib) and by the paltry politicians in Washington and Baghdad who squabble for precedence while lifeblood is spent and spilled by young people whose boots they are not fit to clean.”

On this 10th anniversary, Iraq is no liberal democracy. A cynical joke holds that “the United States won the war, Iran won the peace, and Turkey won the contract.”

Yet that cannot be the final verdict. As we assess the war, we also have to assess what might have happened had the war not been fought.

The main reason that Saddam Hussein’s nuclear program dwindled away after 1996 was that Saddam had run short of money with oil prices falling to $20 a barrel and less. (In 1998, the inflation-adjusted price of oil dropped to the lowest level since the Great Depression.) Iran decelerated its nuclear program at the same time, likely for the same reason. But the economic surge in China and India after 2004 pushed the price of oil back toward $100 a barrel. That surge would have happened, Iraq War or no Iraq War. What kind of force would Saddam have been in the region if his income had tripled or quadrupled?

The glib conclusion that Iran emerged the true winner of the war does not stand scrutiny. As Iraq has stabilized since 2006, Iraqi oil production has accelerated. In 2012, Iraq produced more oil than in any year since before the first Gulf War. Iraq now numbers among the top five oil exporters. The extra oil capacity provided by Iraq has made it easier for European consumers to agree to stiffer sanctions on Iran. Once the world’s No. 3 oil exporter, Iran has now dropped out of the top 10.

The U.S.-led war unleashed a horrible civil war inside Iraq. But as the example of Syria shows, it’s just wrong to assume that Iraq would have been spared a civil war if Saddam had been left in place. The deluge was coming in Iraq, whatever outside powers did. And while the war planners deserve blame for the failure to keep order, the vast majority of the post-2003 casualties inside Iraq were inflicted by other Iraqis, not the coalition forces.

The transformation of the Middle East that George W. Bush promised has arrived, although in a grotesquely ironic form. From Tunisia to Bahrain, authoritarian regimes are toppling. What’s replacing them isn’t “freedom,” but a new—and often harsher—Islamist rule. Yet it’s also true that in the new Middle East, the influence of al Qaeda has waned. Some of the credit goes to the counterterrorism operations that target and kill al Qaeda operatives. The larger reality is that al Qaeda’s mission has become increasingly outdated as radicalized Middle Easterners wage their struggle closer to home.

Over the past 10 years, there have been few days when the war in Iraq was absent from my thoughts. People often ask me whether I have regrets. It seems absurdly presumptuous to answer the question. I could have set myself on fire in protest on the White House lawn and the war would have proceeded without me. And yet ... all of us who advocated for the war have had to do some reckoning. If the war achieved some positive gains, its unnecessary costs—in human life, in money, to the prestige and credibility of the U.S. government—are daunting and dismaying. If we’d found the WMD, it would have been different. If we’d kept better order in Iraq after the overthrow of Saddam, it would have been different. If more Iraqis had welcomed the invasion as we expected, it would have been different. If the case for the war had been argued in a less contrived and predetermined way, it would have been different.

But it wasn’t different. Those of us who were involved—in whatever way—bear the responsibility.

I happened to be in the British House of Commons on the day of the debate to authorize the Blair government to use force against Iraq. (Technically, the motion before the Commons was a motion to adjourn, but everybody agreed on the meaning of the vote.) The Blair government won fewer than half its own M.P.s, but prevailed thanks to support from the Conservative opposition. The speeches in Parliament were answered out of doors by a giant demonstration. I watched from a perch in Trafalgar Square.

One of the marchers recognized me from a TV interview I’d done the day before. An angry crowd soon formed. British protesters have enough U.S. political savvy to recognize the small place of speechwriters in the scheme of things. But I was all they had at hand, so I’d have to do as the target of their anger. More and more of them crowded nearer and nearer to me, shouting more and more angrily. Pretty obviously, I would not just be walking out of there. So I made them an offer: I’d stay for exactly 30 minutes. I’d answer any question they wanted to ask, as fully as I was able. Then I’d leave. They agreed, and I stepped onto the lip of the stone fountain to be heard. And then an unexpected thing happened. As we spoke together, their anger abated. They didn’t like Saddam, most of them, any better than Tony Blair or George W. Bush liked Saddam. What they wanted was to be heard. They felt they were being messaged and manipulated instead. That’s the part of those events a decade ago that I regret the most. Truth never comes wrapped in so many words.