With the withdrawal of the last U.S. troops from Iraq, we’re finally going to get the answer to the core question about that country: Was Iraq the way Iraq was because Saddam was the way Saddam was, or was Saddam the way Saddam was because Iraq is the way Iraq is — a collection of sects and tribes unable to live together except under an iron fist.

Now we’re going to get the answer because both the internal iron fist that held Iraq together (Saddam Hussein) and the external iron fist (the U.S. armed forces) have been removed. Now we will see whether Iraqis can govern themselves in a decent manner that will enable their society to progress — or end up with a new iron fist. You have to hope for the best because so much is riding on it, but the early signs are worrying.

Iraq was always a war of choice. As I never bought the argument that Saddam had nukes that had to be taken out, the decision to go to war stemmed, for me, from a different choice: Could we collaborate with the people of Iraq to change the political trajectory of this pivotal state in the heart of the Arab world and help tilt it and the region onto a democratizing track?

After 9/11, the idea of helping to change the context of Arab politics and address the root causes of Arab state dysfunction and Islamist terrorism — which were identified in the 2002 Arab Human Development Report as a deficit of freedom, a deficit of knowledge and a deficit of women’s empowerment — seemed to me to be a legitimate strategic choice. But was it a wise choice?

My answer is twofold: “No” and “Maybe, sort of, we’ll see.”

I say “no” because whatever happens in Iraq, even if it becomes Switzerland, we overpaid for it. And, for that, I have nothing but regrets. We overpaid in lives, in the wounded, in tarnished values, in dollars and in the lost focus on America’s development. Iraqis, of course, paid dearly as well.

One reason the costs were so high is because the project was so difficult. Another was the incompetence of George W. Bush’s team in prosecuting the war. The other reason, though, was the nature of the enemy. Iran, the Arab dictators and most of all al-Qaida did not want a democracy in the heart of the Arab world, and they tried everything they could — in al- Qaida’s case, hundreds of suicide bombers financed by Arab oil money — to sow enough fear and sectarian discord to make this democracy project fail.

So no matter the original reasons for the war, in the end, it came down to this: Were America and its Iraqi allies going to defeat al-Qaida and its allies in the heart of the Arab world or were al- Qaida and its allies going to defeat them?

Thanks to the Sunni Awakening movement in Iraq, and the surge, America and its allies defeated them and laid the groundwork for the most important product of the Iraq war: the first ever voluntary social contract between Sunnis, Kurds and Shiites for how to share power and resources in an Arab country and to govern themselves in a democratic fashion. America helped to midwife that contract in Iraq, and now every other Arab democracy movement is trying to replicate it — without a U.S. midwife. You see how hard it is.

Which leads to the “maybe, sort of, we’ll see.” It is possible to overpay for something that is still transformational. Iraq had its strategic benefits: the removal of a genocidal dictator; the defeat of al- Qaida there, which diminished its capacity to attack us; the intimidation of Libya, which prompted its dictator to surrender his nuclear program ( and helped expose the Abdul Qadeer Khan nuclear network); the birth in Kurdistan of an island of civility and free markets and the birth in Iraq of a diverse free press. But Iraq will only be transformational if it truly becomes a model where Shiites, Sunnis and Kurds, the secular and religious, Muslims and non- Muslims, can live together and share power.

As you can see in Syria, Yemen, Egypt, Libya and Bahrain, this is the issue that will determine the fate of all the Arab awakenings. Can the Arab world develop pluralistic, consensual politics, with regular rotations in power, where people can live as citizens and not feel that their tribe, sect or party has to rule or die? This will not happen overnight in Iraq, but if it happens over time it would be transformational, because it is the necessary condition for democracy to take root in that region. Without it, the Arab world will be a dangerous boiling pot for a long, long time.

The best case scenario for Iraq is that it will be another Russia — an imperfect, corrupt, oil democracy that still holds together long enough so that the real agent of change — a new generation, which takes nine months and 21 years to develop — comes of age in a much more open, pluralistic society.

The current Iraqi leaders are holdovers from the old era, just like Vladimir Putin in Russia. They will always be weighed down by the past. But as Putin is discovering — some 21 years after Russia’s democratic awakening began — that new generation thinks differently. I don’t know if Iraq will make it. The odds are really long, but creating this opportunity was an important endeavor, and I have nothing but respect for the Americans, Brits and Iraqis who paid the price to make it possible.

THOMAS L. FRIEDMAN writes for The New York Times.