The United States' military participation in the 22 combined checkpoints across the disputed territories in northern Iraq formally ended on August 1. This was an important event because peacekeeping and conflict prevention in Kirkuk and other territories disputed between Baghdad and Erbil have frequently been cited as among the key stabilizing roles that the U.S. military plays in Iraq. And the tripartite Combined Security Mechanism (CSM) of the U.S. military, Iraqi Army, and Kurdish peshmerga did increase coordination between Iraqi government and Kurdistan Regional Government (KRG) security forces while serving as a credible crisis management mechanism. It now faces a leap into the unknown without the U.S. glue that has held it together so far.

Will the phasing out of the U.S. role mean, as one leaked U.S. intelligence report suggested, that without strong and fair third party influence tensions along the Arab-Kurdish line may quickly turn to violence? Or is too much being made of the transition in what was always intended to be a temporary mechanism? 

The answer is a little bit of both. It is unlikely that the U.S. troop withdrawal will lead directly to a conventional military blowout between the Iraqi Army and peshmerga. In all probability, conditions in most disputed areas will be steady on a day-to-day basis.  But its withdrawal will make the situation less stable. The CSM has been a failsafe to prevent episodic crises in individual hotspots from spiraling out of control. Its removal makes the next miscalculation or local standoff more difficult to defuse and potentially graver in its consequences. There almost certainly will be such testing events as the parties jockey to create facts on the ground.

The genesis for the CSM dates back to the summer of 2008, when an Iraqi Army counter-terrorism operation unexpectedly morphed into an effort to roll back Kurdish administration of disputed towns in northeast Diyala. The showdown resulted in a rolling series of standoffs with the Kurdish peshmerga. At one point, U.S. troops even had to interpose themselves between the Kurdish artillery and Iraqi Army tanks involved. In February, local tensions in Kirkuk flared after the peshmerga, without coordinating through the CSM, moved from their authorized positions north of Kirkuk City and dug in south of the town. It took over a month of U.S. prodding to get the peshmerga to re-deploy to their original location.

The shared track record of using military forces to further territorial claims suggests that after the U.S. buffer is withdrawn it is possible that some in Baghdad or Erbil might be tempted to use this tactic once again. 

Right now the Kurds probably have greater incentive to challenge the status quo. In 2008, Arab resentment against perceived Kurdish territorial overreach made the Diyala operation a political winner for Prime Minister Nouri al-Maliki. Currently, in mid-2011, facing persistent challenges from both Iyad Allawi and Muqtada al-Sadr, Maliki relies on Kurdish support to keep his governing coalition together. Accordingly, he can be expected to avoid actions that would alienate the Kurds -- perhaps explaining the surprisingly muted response of the Iraqi government to the February peshmerga deployment in Kirkuk.

Conversely, one straightforward lesson for Kurdish leaders from recent history is that their allies in Baghdad have proven to be tactical rather than permanent. To wit, in 2006 the Kurds were powerful enough to veto candidates for Prime Minister. Two years later they were politically isolated and facing the Iraqi Army in Diyala. The KRG might be considering pushing the envelope before the political winds can change again. If anything this tendency could be reinforced by the relative military position of each side. Since 2003 the peshmerga has generally been seen as better equipped and trained than the significantly larger Iraqi Army. Over time this advantage has eroded to the point where the two forces' capabilities are more or less equally matched. While it's not certain who would have the upper hand in an actual confrontation, the overall trend is clear. Time is not on the Kurdish side in the military realm.

If there is trouble, it would be most likely to develop where there are significant Kurdish populations south of the de facto KRG-federal government line of control marked by the formerly trilateral checkpoints. Two possible hotspots clearly stand out in this respect: Kirkuk City and its immediate surroundings and the disputed towns of Jawala, Sadiya, and Qaratappa in northeast Diyala.

There are substantial Kurdish populations in other parts of the disputed territories (e.g. Khanaqin town, Makhmou,r and certain districts of Ninewa province). But while the final status of these areas is not resolved, they at present have KRG administrative and security control on the ground. Meanwhile, Kirkuk City and the three disputed towns in Diyala are home to the largest concentrations of Kurdish populations in disputed districts secured by Baghdad. Kurdish leaders genuinely feel responsible for the safety of Kurdish populations in these areas as U.S. troops pull-out. Kirkuk City and northeast Diyala have witnessed several insurgent attacks on Kurds and prior to 2003 Saddam Hussein forcibly displaced thousands of Kurds from these areas in order to change the ethnic balance in these districts.

But it is also clear that if the Kurdish security apparatus move into these areas, the chances of their ultimate incorporation into the Kurdistan region would be boosted. This means that special attention should be paid to events in these locales. It is worrying that precisely as U.S. participation in the combined checkpoints ended in July, Kurdish calls for the peshmerga to be sent to Jawala, Sadiya, and Qaratappa to protect Kurdish populations began. These demands have grown steadily louder over the last two weeks, culminating in two peshmerga brigades being mobilized and conflicting reports that they might have already been deployed to Diyala. Given that similar calls to action preceded the surprise peshmerga deployment back in February, the first post-CSM challenge to the status quo could be brewing.          

Even during the heyday of the CSM, U.S. boots on the ground were not the only conflict prevention tool around. A U.S. military presence inside provincial command and control centers for the Iraqi Security Forces allowed for strategic overwatch of events. That presence is still in place and may be continued after 2011 should a continued U.S. military training mission be negotiated. Similarly, the U.S. Embassy has open channels to the Iraqi government and KRG political decision makers. Finally, Turkey is an increasingly central player in northern Iraq. It has developed close ties with KRG and according to one U.S. official played a role in persuading Arab and Turkoman leaders in Kirkuk not to overreact to the February peshmerga deployment.

The handling of the current tensions in Diyala is a potential opportunity to set precedents on the rules of the road for the post-CSM environment. It would be a major setback should some form of peshmerga and Iraqi Army clash occur only weeks after U.S. troops leave the combined checkpoints. At the same time, with the U.S. withdrawal in motion, the trilateral checkpoints are not coming back. The Iraqis need to be able to work through these issues themselves rather than having the United States step in and resolve them. U.S. diplomats and military officers, possibly with reinforcing messages from Ankara, might now encourage senior level Iraqi meetings to directly address the situation in Diyala. The parties should be reminded that the United States is always closely monitoring military movements around Kirkuk City and northeast Diyala and that any unilateral measures will cause a review of future U.S. security assistance to the initiating party.

Messages should also be sent to the KRG that their understandable concerns over the welfare of Kurds in Diyala need to be addressed through existing formal channels rather than by the type of independent action seen in February. Baghdad should likewise be encouraged to respond proactively to fears about Kurds' safety as a way of removing a rationale for a KRG fait accompli that it is not well placed to counter. In the medium term, it probably also makes sense that the limited international resources available for local confidence building should be focused in these specific areas around Kirkuk City and northeast Diyala. With luck, this might build understanding that could help reduce the potential for nasty surprises in this volatile and geo-strategically important area.

Sean Kane is a senior program officer at the United States Institute of Peace and a Truman Security Fellow. The views expressed are his own.