It is time for the United States to leave Iraq.

Not because the consequences of withdrawal won’t be dire for Iraq, but because these consequences are occurring anyway, in slow motion. Civil war and chaos already envelop the country, both conditions are getting worse and the United States is powerless to arrest the downward spiral.

Slowly, but too slowly for those who will die unnecessarily in the meantime, this somber reality is dawning on Washington. The report of the vaunted Baker-Hamilton commission, released December 6, offers a blunt diagnosis of multiple problems besetting the Bush administration Mesopotamian misadventure.

The Iraqi army that is supposed to “stand up” before the United States “stands down?” It is uncertain "whether they will carry out missions on behalf of national goals instead of a sectarian agenda." The new Iraqi police? They “cannot control crime, and they routinely engage in sectarian violence.”

Police and the army, in fact, are too infiltrated by the militias of communal parties to be considered national institutions. They are, in essence, combatants in the multi-sided civil war.

Iraq is a far more violent place than the American media can tell us. Giving the lie to years of right-wing fulmination about a false drumbeat of bad news, the Baker-Hamilton report finds “on one day in July 2006 there were 93 attacks or significant acts of violence reported. Yet a careful review of the reports for that single day brought to light 1,100 acts of violence.”

Meanwhile, those Iraqi civilians who haven’t yet fled to neighboring countries are falling victim to rampant criminality that flourishes in a failing state.

The Baker-Hamilton commission observes that sectarian-ethnic divisions among Iraqi politicians lie at the heart of this horrendous mess, and indeed, since shortly after the fall of Saddam Hussein, these politicians have been playing a zero-sum game. The Kurdish parties looking out for Kurdish interests, the Shiite religious parties guarding Shiite Arab gains, and so on.

Being devotees of bipartisan consensus -- that shiny object of establishment worship -- and heeding White House instructions to “look forward, not backward,” the commissioners neglected to note the US role in dividing the Iraqi polity.

It was L. Paul Bremer, Bush’s erstwhile proconsul in Baghdad, who assigned seats in the first two interim Iraqi governments according to communal affiliation.

It was Bremer’s ham-handed measures and the indiscriminate US counter-insurgency sweeps in the “Sunni triangle” in 2003 that helped convince the bulk of Sunni Arabs they, too, had to organize along communal lines.

Finally, the US presence in Iraq is itself a driver of internecine fighting. Part of the reason for the heavily Sunni Arab insurgency hostility to the Iraqi government is its refusal to demand a timetable for withdrawal of Bush’s “coalition of the willing,” which many Iraqis (not all of them Sunnis) reject as unwanted foreign presence.

Although US troops cannot halt the civil war ravaging Iraq, and although they are not consciously enlisted in it, they are not mere bystanders. In backing the Iraqi government, the United States has taken sides.

Yet Washington cannot simply correct its numerous errors of governance in Iraq because it no longer calls the shots. The democratically elected Iraqi government does -- at least nominally -- but this government’s dominant factions are the main beneficiaries of the sectarian-ethnic calculus underlying post-Saddam Iraqi politics.

They will not seek real national reconciliation voluntarily, and in any case, zero-sum logic dictates they arm themselves for a stepped-up confrontation instead.

An expeditious US withdrawal will not automatically bring peace to Iraq; indeed, the civil war might spread. But neither can the United States stop the meltdown its policies helped start.

The scenarios of which stay-the-coursers have warned -- civil war and lawlessness -- are already stark features of the “new Iraq.” There is no reason to believe keeping US soldiers there any longer will make them disappear.