No doubt the sectarian conflict would escalate if US forces left Iraq. At one time, it might have been possible to have an international peace-keeping force -- which would have more legitimacy than US forces in the eyes of the Iraqis -- take the place of the American troops. That time, however, is long past: having seen the colossal screw-up that the Bush administration has made of Iraq, no other country would want to touch that mess with a ten-foot pole.*
But the sectarian conflict will escalate as long as each side in the conflict (and there are at least three) see some advantage in escalation, regardless of the presence or absence of American troops. For the Kurds, they simply want an autonomous or independent Kurdistan. For the Shiites and Sunnis, they want to dominate whatever is left of Iraq after this is all over (either as defined by its pre-war boundaries or else shorn of Kurdistan and perhaps some other bits of territory).
Unfortunately, the Shiite and Sunni goals of dominance are not only mutually exclusive (only one side can win), but they are fundamentally at odds with the notion of democracy. In other words, the Shiites and Sunnis can only achieve their objective of sectarian dominance in a non-democratic Iraq. That's why the conflict is being played out on the battlefield rather than in the parliament, which no one takes seriously.
If the US's chief concern was stability in Iraq, then it would support one side or the other in the Shiite-Sunni conflict and let the victor impose order. That would work, as Iraqi history has amply demonstrated -- the only times that Iraq has been stable have been those times during which it was ruled by a dictatorship. Of course, such stability would come at the cost of democracy, which would be incompatible with a situation where one group dominates the other. But then
that is the problem: US troops are in Iraq solely because of Washington's chimerical quest to impose democracy on Iraq.
Now, of course, democracy is a really swell form of government, and, all other things being equal, is preferable to living under the rule of a dictator. From the perspective of the average Iraqi, however, I'm not so sure that an ineffectual democracy that is powerless to stop the sectarian violence is preferable to a dictatorship that can impose order and peace on the nation.
From the perspective of US strategic interests, I'm not sure why a dictatorship isn't preferable either. A democracy, after all, has the annoying habit of placing the majority in power, and the Shiites constitute the majority in Iraq. I don't know why the Bush administration is so eager to install a Shiite-led government in Iraq when it has such problems with the Shiite-led government in Iran, but that was a puzzle that should have been solved
before the invasion. Once the US invaded, and made one of its stated goals the creation of a democratic Iraq, the administration was inevitably faced with the burden of creating a Shiite state that would be aligned with Tehran rather than with Washington (despite all of the absurd neo-con predictions to the contrary). Why we should be carrying Iran's coals in this manner is anybody's guess.
The solution, then, to the Iraq crisis is as obvious as it is simple: abandon the notion of creating a democracy in Iraq, install a dictator, and then withdraw all US troops. Such an operation could well be accomplished in six months or less. The nation would be stabilized, there would be a greater likelihood of a pro-US government in Baghdad (or, at least, not so anti-US), and there would be no need for a continued US presence in the country.
*see, I didn't
forget about Poland