The United States should not intervene militarily in Iraq's nascent civil war -- at least not yet.
The breathtaking capture of large swathes of northern Iraq in the last week by a relatively small and lightly armed force of Sunni Arab militants fighting under the banner of the Islamic State in Iraq and the Levant, also known as ISIL or ISIS, has altered the strategic landscape of the Middle East. The successor to al-Qaida in Iraq, ISIL has ridden a wave of resentment felt by Iraq’s Sunni Arabs at the exclusionary sectarian policies pursued by Iraq’s Shiite Prime Minister Nouri al-Maliki.
Its rise has been greatly facilitated by Syria's civil war, which enabled ISIL to establish a base of operations in eastern Syria and to transform itself into a lightly armed, mobile force with thousands of experienced fighters (including many freed prisoners and foreign volunteers). Over a year ago, ISIL began shifting resources back to Iraq, operating openly in the western part of the country, initiating a suicide bombing campaign, and early this year seizing control of several towns in Anbar province, including Fallujah.
The ISIL capture of Mosul and of much of the north of the country, then, is part of a multi-phased plan to establish an Islamic state that extends from Lebanon to Iraq. And the next big target for ISIL may be Baghdad.
But ISIL is unlikely to replicate these spectacular military achievements in the Baghdad area. If the Iraqi security forces were seen by many locals as an army of occupation in northern Iraq, in Baghdad it is defending its home turf, and can rely on the support of the thousands of Shiite militiamen that have been mobilized to fight ISIL, as well as much of the population. Already, ISIL's efforts to take the city of Baquba, northeast of Baghdad, seem to have stalled.
Accordingly, the conflict is likely to take the form of a prolonged and bloody war of attrition. There will be no more easy victories for ISIL, though its ability to wreak havoc in the capital and elsewhere through suicide bombings remains undiminished.
Neither will it be easy for the Iraqi security forces to reclaim many of the areas that were lost to ISIL. They have been trying to do so in Fallujah for months now, without success. For the forces to succeed, they will need to find allies among the Sunnis, in a repeat of the tribal uprising that helped defeat al-Qaida in Iraq in 2006-2007. But having been used and abandoned once before, the tribes won't come around so easily this time.
ISIL also faces challenges. It is spread thin throughout northern Iraq. If it is to hang onto its territorial gains, it will have to hold together the loose military coalition that it leads, which includes Baathist insurgent groups and tribal militias whose interests diverge from those of ISIL. This won't be easy. And it will have to avoid the tendency to alienate the very Sunni constituency it claims to represent by its harsh application of Islamic law. These dynamics will create opportunities for the al-Maliki government if it is smart enough to seize them.
So how should the United States respond?
First, do no harm; don't over-react. There is a good chance that the Iraqi security forces and their militia auxiliaries will be able to keep ISIL at bay on their own. The U.S. should be quietly providing intelligence and advice to the security forces, and it is wise to be positioning forces in the region to provide them with military options. But the United States should not intervene militarily in this nascent civil war -- at least not yet. Force should only be used if the U.S. embassy in Baghdad is threatened by ISIL and its allies. The last thing the U.S. needs is to become an active participant in this fight. Extremists often rely on their enemies overreacting. Direct U.S. intervention would be a recruiting boon for ISIL. Don't grant it this favor.
Second, stop the loose talk about meeting with Iran to discuss the situation in Iraq. This only feeds speculation that Washington and Tehran are conspiring at the expense of the Sunnis, and that the United States believes that the way to fight Sunni jihadists is by allying with Shiite jihadists. This perception will only further complicate the already polarized and fraught situation in Iraq, and foster additional distrust toward the United States among its traditional (Sunni) Arab allies, at a time that it needs their help in finding a middle way in both Syria and Iraq.
Third, Washington should continue to press al-Maliki to seek an alliance with Sunnis opposed to ISIL, in order to reprise the coalition that defeated al-Qaida in Iraq in 2006-2007. During this crisis, al-Maliki has shown that his instinctive response is to play the sectarian card, calling on Shiite militias to rally to the side of the Iraqi security forces against ISIL; while that may yield short-term political dividends, in the long run it is a losing bet. The United States should therefore condition the expedited delivery of additional arms on his reviving a cross-sectarian strategy -- but it should have no illusions that these efforts will succeed, or that al-Maliki will not abandon this strategy once he has achieved his goals (as he has done in the past).
Finally, the road to effectively managing the crisis in Iraq may pass through Syria. ISIL has a major presence in eastern Syria and it is important to put pressure on it there, especially in light of its recent gains, which include quantities of arms taken from the Iraqi security forces. The United States has long debated whether to train and equip the moderate opposition in Syria. Now is the time to finally do so. This will constitute a challenge to ISIL that will almost certainly cause the latter to draw down its forces in Iraq to secure its Syrian sanctuary, thereby relieving some of the pressure on the al-Maliki government, and perhaps force ISIL to loosen its grip over ground it has recently taken. (It will also enable the moderate opposition to keep up the pressure on the Assad regime at a time that the latter's allies from various Iraqi Shiite militias have been called home to fight ISIL.) All this will take time, but neither crisis is likely to abate soon, while training and equipping the moderate Syrian opposition has the potential to yield important benefits as part of a long-term U.S. strategy toward both Syria and Iraq.
Michael Eisenstadt directs the Military and Security Studies Program at The Washington Institute.
U.S. News & World Report