Hunker down and wait for the smoke to clear. This isn't a bad option, all told. The U.S. military has been steadily moving in this direction for a year or so already. Its larger bases in Iraq are quite secure, though protecting the supply lines to the bases might be tougher under the circumstances.
And here's where Baker, Hamilton, & Co.'s diplomatic proposal—to start talking with Syria, Iran, and the other regional powers—might have some impact. It's hard to justify keeping even 50,000 American troops in Iraq—even if they're just sitting there—unless they have a mission. One mission might be to serve as adjunct to a broader political initiative.
If Iraq falls apart, the bordering states will be tempted to rush into the vacuum, partly for their own security, partly for aggrandizement. If they do, their forces may brush up against one another (Iraq's internal sectarian borders are far from distinct). The United States could serve as a mediator to keep this from happening. To play this role, it helps to have troops on the ground and planes in the air.
This may be the only real purpose of a U.S. military presence in Iraq at this point—to keep the country and the region from erupting into flames. And it won't be possible to accomplish even this purpose without open cooperation with the neighboring countries, including—perhaps especially—Iran.
The days of America's unilateral influence in Iraq are long over, if they weren't mythical from the outset. Look at this week's fiasco. Prime Minister Maliki canceled a dinner with President Bush—just brushed off the president of the United States, the country that's sacrificed thousands of young men and women and spent hundreds of billions of dollars to keep Maliki's government standing—because keeping the date would have upset Muqtada Sadr, the most powerful Shiite militia leader, who apparently now has more leverage than the United States and its 150,000 troops.
It's pathetic, but it's also a wake-up call. Our leverage is minuscule, and it's declining by the day. To talk of grand schemes—partitioning Iraq or pressuring Maliki to form a "reconciliation government" and amend his constitution—is, quite apart from their merits, plainly absurd, because we have no control over what the Iraqis do. We still have some control, though, over what we do and, maybe, over what we can persuade others to do with us. The only choices are to give persuasion a whirl or to sit and watch a piece of the world fall apart.
It's clear that we do not possess the political will to send hundreds of thousands more soldiers to Iraq (and there's no guarantee that such an approach would eventually end the violence anyway.) As it has become increasingly clear that our troops can no longer serve as a cap on the violence, it has become equally clear that it serves no purpose to allow them to continue to die in such numbers when they can no longer hope to hold the country together. At the same time, as Kaplan suggests, it may not be necessary to bring them all home. We might be able to limit their mission and thus their exposure, while still helping to keep the country from falling apart and protecting our interests in the country. It's an option at least, worth further discussion.