The Bush administration famously based its argument for invading Iraq on best-case assumptions: that we would be greeted as liberators; that a capable democratic government would quickly emerge; that our military presence would be modest and temporary; and that Iraqi oil revenues would pay for everything. All these assumptions, of course, turned out to be wrong.

Now, many of the same people who pushed for the invasion are arguing for escalating our military involvement based on a worst-case assumption: that if America leaves quickly, the Apocalypse will follow. How would [advocates of withdrawal] respond to the eruption of full-blown civil war in Iraq and the massive ethnic cleansing it would produce? write Robert Kagan and William Kristol in the Weekly Standard. How would they respond to the intervention of Iraqs neighbors, including Iran, Syria, and Turkey? And most important, what would they propose to do if, as a result of our withdrawal and the collapse of Iraq, al Qaeda and other terrorist groups managed to establish a safe haven from which to launch attacks against the United States and its allies?

Similar rhetoric has been a staple of President Bushs recent speeches. If the United States fails in Iraqhis euphemism for withdrawalthe president said in January, [r]adical Islamic extremists would grow in strength and gain new recruits. They would be in a better position to topple moderate governments, create chaos in the region, and use oil revenues to fund their ambitions Our enemies would have a safe haven from which to plan and launch attacks on the American people.

This kind of thinking is also accepted by a wide range of liberal hawks and conservative realists who, whether or not they originally supported the invasion, now argue that the United States must stay. It was evident in the Iraq Study Group, led by James Baker and Lee Hamilton, which, participants say, was alarmed by expert advice that withdrawal would produce potentially catastrophic consequences. Even many antiwar liberals believe that a quick pullout would cause a bloodbath. Some favor withdrawal anyway, to cut our own losses. Others demur out of geostrategic concerns, a feeling of moral obligation to the Iraqis, or the simple fear that Democrats will be blamed for the ensuing chaos.

But if it was foolish to accept the best-case assumptions that led us to invade Iraq, its also foolish not to question the worst-case assumptions that undergird arguments for staying. Is it possible that a quick withdrawal of U.S. forces will lead to a dramatic worsening of the situation? Of course it is, just as its possible that maintaining or escalating troops there could fuel the unrest. But its also worth considering the possibility that the worst may not happen: What if the doomsayers are wrong?

The al-Qaeda myth

To understand why its a mistake to assume the worst, lets begin with the most persistent, Bush-fostered fear about post-occupation Iraq: that al-Qaeda or other Islamic extremists will seize control once America departs; or that al-Qaeda will establish a safe haven in a rump, lawless Sunnistan and use that territory as a base, much as it used Taliban-controlled Afghanistan.

The idea that al-Qaeda might take over Iraq is nonsensical. Numerous estimates show that the group called Al Qaeda in Iraq (AQI) and its foreign fighters comprise only 5 to 10 percent of the Sunni insurgents forces. Most Sunni insurgents are simply what Wayne Whitewho led the State Departments intelligence effort on Iraq until 2005calls POIs, or pissed-off Iraqis, who are fighting because they dont like the occupation. But the foreign terrorist threat is frequently advanced by the Bush administration, often with an even more alarming variantthat al-Qaeda will use Iraq as a headquarters for the establishment of a global caliphate. In December 2005, Rear Admiral William D. Sullivan, vice director for strategic plans and policy within the Joint Chiefs of Staff, delivered a briefing in which he warned that al-Qaeda hoped to revive the caliphate, with its capital in Baghdad. President Bush himself has warned darkly that after controlling Iraq, Islamic militants will establish a radical Islamic empire that spans from Spain to Indonesia.

The reality is far different. Even if AQI came to dominate the Sunni resistance, it would be utterly incapable of seizing Baghdad against the combined muscle of the Kurds and the Shiites, who make up four fifths of the country. (The Shiites, in particular, would see the battle against the Sunni extremist AQIwhich regards the Shiites as a heretical, non-Muslim sectas a life-or-death struggle.)

Nor is it likely that AQI would ever be allowed to use the Sunni areas of Iraq as a base from which to launch attacks on foreign targets. In Afghanistan, al-Qaeda had a full-fledged partnership with the Taliban and helped finance the state. In Iraq, the secular Baathists and former Iraqi military officers who lead the main force of the resistance despise AQI, and many of the Sunni tribes in western Iraq are closely tied to Saudi Arabias royal family, which is bitterly opposed to al-Qaeda. AQI has, at best, a marriage of convenience with the rest of the Sunni-led resistance. Over the past two years, al-Qaeda-linked forces in Iraq have often waged pitched battles with the mainstream Iraqi resistance and Sunni tribal forces. Were U.S. troops to leave Iraq today, the Baathists, the military, and the tribal leaders would likely join forces to exterminate AQI in short order.

Its also worth questioning whether the forces that call themselves Al Qaeda in Iraq have any real ties to whatever remains of Osama bin Ladens weakened, Pakistan-based leadership. Such ties, if they exist, have always been murky at best, even under the leadership of Abu Musab al-Zarqawi. With al-Zarqawis elimination in 2006 and his replacement by a collegial group, these ties are even muddier. Although its convenient for the Bush administration to claim that al-Qaeda is a Comintern-like international force, it is really a loose ideological movement, and its Iraq component is fed largely by jihadists who flock to the country because they see the war as a holy cause. Once the United States withdraws, Iraq will no longer be a magnet for that jihad.

The Sunni-Shiite civil war

The doomsayers second great fear is that the Sunni-Shiite sectarian civil war could escalate further, reaching near-genocidal levels and sucking in Iraqs neighbors. The biggest danger as we draw down is that the Shiites will run roughshod over the Sunnis, says Brian Katulis of the Center for American Progress, whose exit strategy, Strategic Redeployment 2.0,
is a blueprint for many Democrats on Capitol Hill. Similarly, Wayne White, who advised the Baker-Hamilton ISG, says that because of Baghdads importance, both Sunni and Shiite forces would probably rush to fill a vacuum in the capital if the United States withdraws.

In fact, its hard to find an analysis of the Iraq crisis that doesnt predict an expanded Sunni-Shiite war once the United States departs. But lets look at the countervailing factorsand there are many.

First, the United States is doing little, if anything, to restrain ethnic cleansing, either in Baghdad neighborhoods or Sunni and Shiite enclaves surrounding the capital. Indeed, under its current policy, the United States is arming and training one side in a civil war by bolstering the Shiite-controlled army and police.

In theory, Baghdad is roughly divided into Shiite east Baghdad on one side of the Tigris River, and Sunni west Baghdad on the other side. But in isolated neighborhoods such as Adhamiya, a Sunni part of east Baghdad, and Kadhimiya, a Shiite enclave in west Baghdad, ugly ethnic cleansing is proceeding apace. The same is true along a necklace of Sunni towns south of the capital, in an area that is predominantly Shiite; in mixed Sunni-Shiite towns such as Samarra, the largest city of predominantly Sunni Salahuddin Province, north of Baghdad; and in Diyala Province, northeast of Baghdad. In these areas, it is facile to assert that U.S. troops are restraining the death squads and religiously inspired killers on both sides. And it would be impossible for us to do so even with a much greater increase in American troops than the president has called for.

Second, although battle lines are hardening and militias on both sides are becoming self-sustaining, the civil war is limited by physical constraints. Neither the Sunnis nor the Shiites have much in the way of armor or heavy weaponstanks, major artillery, helicopters, and the like. Without heavy weaponry, neither side can take the war deep into the others territory. Theyre not good on offense, says Warren Marik, a retired CIA officer who worked in Iraq in the 1990s. They cant assault positions. Shiites may have numbers on their side. But because the Sunnis have most of Iraqs former army officers, and their resistance militia boasts thousands of highly trained soldiers, theyre unlikely
to be overrun by the Shiite majority. Equally, the minority Sunnis wont be able to seize Shiite parts of Baghdad or major Shiite cities in the south. Presuming neither side gets its hands on heavy weapons, once you take U.S. forces out of the equation the Sunnis and Shiites would ultimately reach an impasse.

Even if post-occupation efforts to create a new political compact among Iraqis fail, the most likely outcome is, again, a bloody Sunni-Shiite stalemate, accompanied by continued ethnic cleansing in mixed areas. But that, of course, is no worse than the path Iraq is already on under U.S. occupation.

A third fear is that Iraqs neighbors will support their proxies in this fight. Indeed, they probably willbut within limits. Iran, which is already assisting various Shiite parties (especially the Supreme Council for the Islamic Revolution in Iraq), would continue to do so. And Sunni Arab states like Saudi Arabia, Egypt, and Jordan would line up behind Iraqs Sunnis. Even so, neither Shiite Iran nor the Sunni Arab countries would likely risk a regional conflagration by providing their Iraqi proxies with the heavy weapons that would enable them to wage offensive operations in each others heartland.

The only power that could qualitatively worsen Iraqs sectarian civil war is the United States. Washington continues to arm and train the Shiites, although so far it has resisted Prime Minister Nouri al-Malikis pleas to provide Iraqs Shiite-led army and police with heavy weapons, armor, and an air force. Only if that policy changed, and the United States began to create a true Shiite army in Iraq, would the Sunni Arab states likely feel compelled to build up Iraqs Sunni paramilitary militias into something resembling a traditional army.

Thus, even if we assume that Iraqs parties cannot achieve some sort of reconciliation as the United States withdraws, an American pullout is hardly guaranteed to unleash unbridled chaos. On the contrary, each year since 2003 that American troops have remained in Iraq, the violence has escalated steadily.

A Kurdish power grab?

The third major concern about a post-occupation Iraqalthough it gets less attention than it deservesis the possibility of a crisis triggered by a Kurdish power grab in Kirkuk, the city at the heart of Iraqs northern oil fields. Since 2003, the Kurds have been waging a systematic, ugly round of ethnic cleansing, packing Kirkuk with Kurds, kidnapping or driving out Arab residents (many of them settled there by Saddam), and stacking the city council with Kurdish partisans.

Though Kurdish Iraq is mostly quiet and relatively prosperous under the Kurdistan Regional Government that controls three northeastern provinces, the Kurds may be tempted to expand their territory and secede from Iraq. Under the occupation-imposed constitution, the Kurds have the right to hold a referendum in Kirkuk later this year that would probably put that oil-rich area under the control of the KRG; the Baker-Hamilton ISG called the referendum explosive and recommended that it be postponed. Alternatively, the Kurds might opt to take advantage of the Sunni-Shiite civil war to seize Kirkuk by force. Either way, most Kurds know that a Kurdish-controlled Kirkuk is an essential precondition for their ultimate independence from Iraq.

Its hard to exaggerate the dangers inherent in a Kurdish grab for Kirkuk. Such a move would inflame Iraqs Arab population (both Sunnis and Shiites), impinge on other minorities (including Turkmen and Christians), and provoke an outburst of ethnic cleansing in the city. Iraqs two-sided civil war would become a three-sided affair.

But although this scenario sounds alarming, the reality is that, in the event of an American withdrawal, the Kurds would find it exceedingly difficult either to take Kirkuk or to declare independence. An independent Kurdistan would be landlocked, surrounded by hostile nations, and would possess a weak paramilitary army incapable of matching Iran, Arab Iraq, or Turkey. If Kurdistan were to secede without gaining Kirkuks oil, it would not be an economically viable nation. Even with the oil, the Kurds would have to depend on pipelines through Iraq and Turkey to export any significant amount. Nor would Turkey, with its large Kurdish minority, stand for a breakaway Kurdish state, and the Kurds know that the Turkish armed forces would overwhelm them.

Conversely, under the U.S. occupationor, perhaps, because of itthe Kurds apparently feel emboldened to press their advantage in Kirkuk, despite the dire consequences. And if the United States were to adopt the idea floated by some in Washington of building permanent bases in Kurdistan, it would embolden the Kurds further. (The threat of a Turkish invasion is the chief deterrent to any move by the Kurds against Kirkuk, but as long as the United States maintains a presence in Kurdistan, the Turks will be reluctant to check the Kurds, for fear of running into U.S. troops.) Thus, by staying or by creating bases in Kurdistan, the United States is more likely to foster a Kurdish-Arab civil war in Iraq.

Will the center hold?

Not only is the worst-case scenario far from a sure thing in the event of an American withdrawal, but there is also a best-case scenario. Precisely because the idea of all-out civil war and a regional blowup involving Iran, Saudi Arabia, and Turkey is so horrifying, all the political forces inside and outside Iraq have many incentives not to go there.

Certainly, four years into the war, passions on all sides have been inflamed, communal tensions bared, and the secular, urban Iraqi middle class has either fled or been decimated. The mass terror perpetuated by armed gangs of extremists now occupies center stage. The broken Iraqi state has ceased to exist outside the Green Zone, the economy is devastated, and unemployment is believed to be hovering around 50 percent.

Yet the neoconservatives and the Bush administration werent entirely wrong in 2003 when they expressed confidence in the underlying strength of the Iraqi body politic. Though things have gone horrendously awry, there are many factors that could provide the glue to put Humpty Dumpty back together again.

Contrary to the conventional wisdom in Washington, Iraq is not a make-believe state cobbled together after World War I, but a nation united by the Tigris and Euphrates rivers, just as the Nile unites Egypt. Historically, the vast majority of Iraqis have not primarily identified themselves according to their sect, as Sunnis or Shiites. Of course, as the civil war escalates, more Iraqis are identifying by sect, and tensions are worsening. But it is not too late to resurrect some of the comity that once existed. The current war is not a conflict between all Sunnis and all Shiites, but a violent clash of extremist paramilitary armies. Most Iraqis do not support the extremists on either side. According to a poll conducted in June 2006 by the International Republican Institute, seventy-eight per cent of Iraqis, including a majority of Shiites, opposed the division of Iraq along ethnic and sectarian lines.

In addition, the countrys vast oil reserves, conceivably the worlds largest, could help hold Iraq together. Iraqi politicians are currently devising a law that would ratify the central governments control of all of the countrys oil wealth. Even the corruption that now cripples Iraq tethers Iraqi political leaders to the central government and to the idea of Iraq as a nation-state. None of the big players really want civil war, says an Iraqi military official closely affiliated with Ahmad Chalabis Iraqi National Congress. None of them want to give up the regular flow of funds that they get now from corruption.

What most Iraqis do seem to want, according to numerous polls, is for American forces to leave. Even within the current, skewed Iraqi political system, a majority of Iraqs parliament supports a U.S. withdrawal. If we add to the mix the powerful Sunni-led resistance, including former Baathists, Sunni nationalists, and tribes, an overwhelming majority wants to end the occupation.

This shared desire could be another crucial force in helping maintain the integrity of Iraq. The catch-22 of Iraqi politics is that any Iraqi government created or supported by the United States is instantly suspect in Iraqi eyes. By the same token, a nationalist government that succeeds in ushering U.S. forces out of Iraq would have overwhelming support from most Iraqis on most sides of the conflict. With that support, such a government might be able to make the difficult compromiseslike amending the constitution to give minority protections to Sunnisthat the Maliki government has been unable or unwilling to make but that most observers believe are crucial to any political settlement that might end the fighting.

It is clear that there are many features of Iraqs current landscape that lend themselves to the eventual creation of a stable, postwar nationalthough rebuilding the country will take generations. It is, at this point, the best we can hope for. Like all best-case scenarios, it might or might not happen. But the very same can be said of the worst-case scenarioa scenario that war hawks portray as a certainty and wave, like a bloody shirt, to scare decision-makers and members of Congress into supporting a failed strategy.