It's hard to understand why the Obama administration would consider leaving only about 3,000 U.S. troops in Iraq after 2011. A force so small would have little ability to contribute to U.S. interests by helping to build a democratic Iraq or by preventing it from sliding back into civil war. But it would incur all the risks and costs of a continuing troop presence.
A few thousand troops would have some residual capacity to provide training and modest logistical support for the Iraqi Security Forces. But that's about it.
They certainly will not be in any position to play the vital peacekeeping role that produced the phenomenal drop in violence starting in early 2007 and that made possible Iraq's hopeful - but entirely incomplete - democratic progress in 2008-2010. The loss of that role could well result in a relapse of Iraq's civil war that might suck in neighboring states and metastasize from civil war to regional war.
A U.S. force so small will have little, if any, intelligence-gathering capacity or situational awareness. It certainly won't be able to support Iraqi development and reconstruction.
Even with regard to training and logistical support (the Iraqis still need both, the latter more than the former), a few thousand U.S. personnel will not be able to provide the same levels of training that U.S. forces have in the past. Both the partnering of U.S. and Iraqi units in the field and the attaching of American advisers to Iraqi formations will have to be cut back.
Perversely, training and logistics are the only two areas where the Iraqis may not even need military help. They could, in fact, go out and hire Western contractors to do the job for them, because in these areas contractors actually are a reasonable substitute for U.S. forces. In short, we could be leaving a force in place that is only capable of performing missions that U.S. troops are not uniquely necessary to perform.
A force of only a few thousand Americans also will have a greatly reduced capacity to undertake unilateral counterterrorism operations. That mission must then be left largely to the Iraqis, who have proven able but not always willing - especially when Iraq's own complicated politics make it inconvenient to hunt down death squads and terrorists.
This is where the idea of leaving only a few thousand U.S. troops in place goes from perplexing to potentially dangerous. A force that small will have a very hard time protecting itself, let alone other American personnel in Iraq. They will have to remain on a small number of forward operating bases that are well known to Iraq's myriad terrorist groups, who will continue to attack them for a variety of emotional and political reasons. But our troops will not have all of the intelligence assets that they have enjoyed in the past to identify potential threats; the special-forces capabilities to pre-empt attacks; the heavy weapons to quickly respond to attacks; or the assets to track down the perpetrators of an attack and catch or kill them.
Force protection, which had become almost a non-issue by 2010, has already resurfaced as a problem after the reduction to 46,000 troops late last year. If not for the Herculean efforts of the U.S. military command in Baghdad this summer to convince the Iraqi government to take protecting U.S. troops seriously, the soldiers might already be in an untenable position - and with 15 times the number of troops that future plans call for. With only a few thousand troops left in Iraq, and the U.S. military lacking the weight to press Baghdad to do the right thing, force protection could become impossible.
There is another problem. As we have seen recently during violent protests in Bahrain, when American military personnel are present in a country, the U.S. is seen as responsible for developments there. No matter how tiny a U.S. force remains in Iraq, the perception in the Arab world will be that the Americans are in charge behind the scenes. Any problematic actions undertaken by whatever Iraqi faction is in government against its rivals - a common problem that has plagued Iraq and is the surest way to reignite civil war - will be perceived as having Washington's backing. The fact that we will have little ability to affect the situation will be lost on Iraqis, who will see complicity, not impotence.
Which raises the question: If the administration is unwilling to keep a force in Iraq large enough to have some positive impact on Iraq's critical but precarious political development, is there any reason to keep troops there at all and incur the risks they will inevitably face? A total pullout would mean risking everything that Americans and Iraqis have achieved there, and courting another civil war in a region that cannot afford one. But leaving just 3,000 troops in harm's way is effectively doing the same thing.