Can U.S. and Iran work together in Iraq?

The recent military conquest of much of Iraq by the Islamic State of Iraq and the Levant (ISIL) has ignited a debate on Iran’s role. Analysts and pundits have asked: Should Washington work with Tehran to stem ISIL’s seemingly inexorable march? U.S.-Iran cooperation seems possible, if not desirable, on the surface. Both Washington and Tehran fear ISIL and related extremist Sunni groups, and negotiations between the two on Iran’s nuclear program could lead to greater engagement on other issues, particularly Iraq. But close U.S.-Iran cooperation on Iraq at this point is fraught with complications. American and Iranian interests are not neatly aligned in Iraq. And cooperation between the two could complicate the nuclear negotiations by giving Tehran more leverage, making U.S. allies such as Saudi Arabia and Israel more nervous, and strengthening congressional opposition to a future nuclear deal.

The Islamic Republic of Iran will do all it can to make sure ISIL does not take Baghdad and destroy the Shia holy shrines of Najaf and Karbala. Such an outcome would be a serious blow to the Iranian regime’s geopolitical and religious interests. It is no surprise that the Iranian Revolutionary Guard has increased its activities in Iraq and is mobilizing thousands of loyal Iraqi Shia militiamen in an effort to stop ISIL in its tracks. And it would not be surprising to see Iran send more of its forces into Iraq, or even intervene overtly if Baghdad is in danger of falling. Gen. Mohammad Ali Jafari, the Guard’s chief, recently stated that Iran was an “island of stability” in the Middle East because of its success in withstanding Iraq’s onslaught from 1980 to 1988. Although Iran did not win the war, the subsequent overthrow of Saddam Hussein by the U.S. and the empowerment of the Shia in Baghdad vindicated the Guard’s sacrifices during its “sacred defense” of Iran. The fall of the Shia in Iraq would be a strategic setback for the Iranian regime.

But does this mean that Iran is willing to work with the U.S.? The government of President Hassan Rouhani seems to believe so. His advisers have gushed enthusiastically on the possibility of cooperation with Washington, viewing it as facilitating not only nuclear negotiations, but also Rouhani’s foreign policy of moderation and engagement. But Supreme Leader Ayatollah Ali Khamenei has publicly opposed working with Washington. And it is difficult to envision Gen. Qasem Soleimani, the Guard commander responsible for Iranian operations in Syria and Iraq, working with uniformed American soldiers. After all, Soleimani’s Qods Force was responsible for hundreds of U.S. deaths and injuries during the occupation of Iraq. Of course, the U.S. can adopt the pragmatic position that “the enemy of my enemy is my friend” and work with Iran, its (arguably) most capable foe in the Middle East. But the wounds on both sides may be too recent and raw for such realpolitik.

And, engagement with Iran on issues beyond the nuclear program would undoubtedly create greater anxiety in Tel Aviv and Riyadh. The Israeli and Saudi governments are convinced that Iran is on the “march” in the Middle East. This view is debatable, and not always terribly nuanced, but it could nevertheless complicate nuclear negotiations, especially given the Israeli government’s vociferous opposition to the November 2013 interim nuclear deal. Even a “good” nuclear deal between Iran and the U.S. may be viewed as a loss for Israeli and Saudi interests if sanctions are lifted and the Guard is freer to spend more lavishly on the Syrian regime and the increasingly sectarian Baghdad government.

The U.S. has maintained that the solution to the Iraq crisis is a more inclusive government in Baghdad. The Iranian government also speaks of inclusiveness in Iraq, but Tehran’s policies are motivated by sectarianism above all else. The Guard will not only seek to bolster the official Iraqi armed forces, but, more importantly, the Shia militias responsible for sectarian killings. Mass sectarian cleansing by both Sunni insurgents and Shia forces backed by Iran is a horrifying but real possibility. Tehran has been willing to support the Syrian regime’s campaign of terror; it may not hesitate to replicate the same policy in Iraq. Washington cannot be complicit in a war of sectarian slaughter.

Despite all of this, Iran is going to have a major role in Iraq whether Washington likes it or not. If the U.S. pursues a “regional” solution to Iraq, it cannot be successful without Iran; the same can be said about the conflict with Syria. The presence of Iranian and American troops in Iraq may necessitate clear and direct communications between the two sides, at least to prevent misunderstanding and greater chaos. But Washington should tread carefully and focus on nuclear negotiations for now. The U.S. can wait to see if a possible nuclear deal presents new opportunities for working with Iran on regional issues, but the maxim “the enemy of my enemy is my friend” may not apply to Iraq at this time.

Alireza Nader is a senior international policy analyst at the nonprofit, nonpartisan Rand Corp. and author of “The Days After a Deal With Iran: Continuity and Change in Iranian Foreign Policy” (Rand).