WASHINGTON -- The barbarism in Mumbai and the economic crisis at home have largely overshadowed an otherwise singular event: the ratification of military and strategic cooperation agreements between Iraq and the United States.

They must not pass unnoted. They were certainly noted by Iran, which fought fiercely to undermine the agreements. Tehran understood how a formal U.S.-Iraqi alliance endorsed by a broad Iraqi consensus expressed in a freely elected parliament changes the strategic balance in the region.

For the United States, it represents the single most important geopolitical advance in the region since Henry Kissinger turned Egypt from a Soviet client into an American ally. If we don't blow it with too hasty a withdrawal from Iraq, we will have turned a chronically destabilizing enemy state at the epicenter of the Arab Middle East into an ally.

Also largely overlooked at home was the sheer wonder of the procedure that produced Iraq's consent: classic legislative maneuvering with no more than a tussle or two -- tame by international standards (see YouTube: "Best Taiwanese Parliament Fights Of All Time!") -- over the most fundamental issues of national identity and direction.

The only significant opposition bloc was the Sadrists, a mere 30 seats out of 275. The ostensibly pro-Iranian religious Shiite parties resisted Tehran's pressure and championed the agreement. As did the Kurds. The Sunnis put up the greatest fight. But their concern was that America would be withdrawing too soon, leaving them subject to overbearing and perhaps even vengeful Shiite dominance.

The Sunnis, who only a few years ago had boycotted provincial elections, bargained with Prime Minister Nouri al-Maliki, trying to exploit his personal stake in agreements he himself had negotiated. They did not achieve their maximum objectives. But they did get formal legislative commitments for future consideration of their grievances, from amnesty to further relaxation of the de-Baathification laws.

That any of this democratic give-and-take should be happening in a peaceful parliament just two years after Iraq's descent into sectarian hell is in itself astonishing. Nor is the setting of a withdrawal date terribly troubling. The deadline is almost entirely symbolic. U.S. troops must be out by Dec. 31, 2011 -- the weekend before the Iowa caucuses, which, because God is merciful, will arrive again only in the very fullness of time. Moreover, that date is not just distant but flexible. By treaty, it can be amended. If conditions on the ground warrant, it will be.

True, the war is not over. As Gen. David Petraeus repeatedly insists, our (belated) successes in Iraq are still fragile. There has already been an uptick in terror bombings, which will undoubtedly continue as what's left of al-Qaeda, the Sadrist militias and the Iranian-controlled "special groups" try to disrupt January's provincial elections.

The more long-term danger is that Iraq's reborn central government becomes too strong and, by military or parliamentary coup, the current democratic arrangements are dismantled by a renewed dictatorship that abrogates the alliance with the United States.

Such disasters are possible. But if our drawdown is conducted with the same acumen as was the surge, not probable. A self-sustaining, democratic and pro-American Iraq is within our reach. It would have two hugely important effects in the region.

First, it would constitute a major defeat for Tehran, the putative winner of the Iraq War according to the smart set. Iran's client, Moqtada al-Sadr, still hiding in Iran, was visibly marginalized in parliament -- after being militarily humiliated in Basra and Baghdad by the new Iraqi security forces. Moreover, the major religious Shiite parties were the ones who negotiated, promoted and assured passage of the strategic alliance with the U.S., against the most determined Iranian opposition.

Second is the regional effect of the new political entity on display in Baghdad -- a flawed yet functioning democratic polity with unprecedented free speech, free elections and freely competing parliamentary factions. For this to happen in the most important Arab country besides Egypt can, over time (over generational time, the timescale of the war on terror), alter the evolution of Arab society. It constitutes our best hope for the kind of fundamental political-cultural change in the Arab sphere that alone will bring about the defeat of Islamic extremism. After all, newly sovereign Iraq is today more engaged in the fight against Arab radicalism than any country on earth, save the United States -- with which, mirabile dictu, it has now thrown in its lot.