The New York Times ventures where Barack Obama fears to tread.  In his profile of General David Petraeus, Dexter Filkins admits what everyone but Harry Reid, Nancy Pelosi, and the Democratic presidential nominee understands — that the change in tactics and manpower at the beginning of 2007 dramatically improved the fortunes of Iraq and the war on terror.  Now, with Petraeus ready to take his well-deserved promotion, he warns that it could still slip through our fingers:

The arrival of the 30,000 extra soldiers, deployed to Baghdad’s neighborhoods around the clock, allowed the Americans to exploit a series of momentous events that had begun to unfold at roughly the same time: the splintering of Moktada al-Sadr’s militia, the Mahdi Army; the growing competence of the Iraqi Army; and most important, the about-face by leaders of the country’s Sunni minority, who suddenly stopped opposing the Americans and joined with them against Al Qaeda in Mesopotamia and other local extremist groups.

The surge, clearly, has worked, at least for now: violence, measured in the number of attacks against Americans and Iraqis each week, has dropped by 80 percent in the country since early 2007, according to figures the general provided. Civilian deaths, which peaked at more than 100 a day in late 2006, have also plunged. Car and suicide bombings, which stoked sectarian violence, have fallen from a total of 130 in March 2007 to fewer than 40 last month. In July, fewer Americans were killed in Iraq — 13 — than in any month since the war began.

The result, now visible in the streets, is a calm unlike any the country has seen since the American invasion toppled Saddam Hussein in April 2003. The signs — Iraqi families flooding into parks at sundown, merchants throwing open long-shuttered shops — are stunning to anyone who witnessed the country’s implosion in 2005 and 2006.

To be fair, the caveat “At least for now” does not come from Filkins’ imagination, but from Petraeus himself.  He warns that an attempt to rapidly remove American troops from Iraq could open the door to militias, insurgents, and terrorists all over again.  Iraqi security still depends on bedrock support from the American military, and will for the next several years.  The scope of the mission and the level of troops may change, but the commitment has to remain solid if Iraqis are to have enough confidence in their nation to allow stability.

That means that succeeding American administrations cannot be hampered with policies dreamt up before Iraq improved.  The surge cannot keep going, as Iraqis will increasingly resent American “occupation” in their cities beyond the point when the Iraqis can handle security there.  In the same way, a hasty retreat — which sounded rational when the country was dissolving into ethnic chaos — has even less application now.  Nor can the Biden Plan of ethnic division of Iraq get any serious consideration for a country that has moved well along the way to political reconciliation.

Stability in Iraq will come from a joint effort between Washington and Baghdad to plan for the future, not stay stuck in the declarations of the past.  If we run away now, we will have thrown away victory and left Iraq to the tender mercies of terrorists, militias, and Iran.   That would deliberately make Iraq into a Somalia with massive oil wealth and strategic implications that will threaten American interests for decades.