The assault on Raqqa, the capital of the Islamic State’s self-declared caliphate, is about to begin, and the end of ISIS is in sight. But so is the end of the tacit tactical alliance between Iran and the United States.
For a time, the old adversaries cooperated against their common enemy. The United States provided the Iraqi government and Iranian-backed Shiite militias with air support to help them seize control over the Iraqi cities of Tikrit in April 2015 and large parts of Mosul by February 2017. However, as these same Iraqi Shiite militias pursue fleeing ISIS elements to oil-rich Deir Ezzour in neighboring Syria, they confront United States special-operations forces and an American-backed coalition of Syrian rebel groups.
In Iraq, the U.S. is working with Iraqi government forces and Iranian-backed Shiite militias in a joint struggle against ISIS. In Syria however, the United States supports the moderate opposition to Bashar al-Assad’s regime, while Iran and its Shiite proxies are engaged in a relentless effort to eliminate opposition forces and secure the survival of the very same regime.
On Tuesday, June 6, U.S.-led coalition fighter jets bombed Syrian government soldiers and, according to some reports, Shiite Iraqi militia members in the al-Tanf region in southeastern Homs province, where since May 2015 a contingent of U.S. troops has been training Syrian opposition forces. It was the second time in less than a month that coalition forces had attacked Syrian regime forces and their allies as they headed toward the al-Tanf garrison. On May 18, coalition planes pounded a convoy headed toward al-Tanf.
The scene is set for a zero-sum game: Iran and its allied Shiite militias want the area to establish an overland corridor to the Syrian-Israeli border, the Mediterranean, and Lebanon. In the first year of the Syrian Civil War, the late Iranian president Akbar Hashemi Rafsanjani likened such an overland corridor to a “string of pearls” [reshteh-ye morvarid] that would connect Iran with its regional allies all the way from western Afghanistan to Lebanon, allowing Tehran to consolidate its sphere of influence across the Levant and facilitate arms shipments to Hezbollah. The American strategy is not clear, but the United States needs to control the area to cut Iran’s expansionism, which is causing alarm among Washington’s key Arab allies and Israel. Unrestricted Iranian access to Lebanese Hezbollah is not only likely to further strengthen the organization, but risks emboldening the group to provoke another war with Israel.
Iran and its Shiite coalition, which has sacrificed blood and treasure to maintain control over Syria, is not likely to restrain itself in the endgame against ISIS. Four hundred and ninety Iranians, 1,063 Lebanese Hezbollah fighters, 653 Afghans, 144 Pakistanis, and at least 94 Iraqi Shia, by my count, have sacrificed their lives in Syria, and they did not do so just to back off at the last moment. Nor is the Trump administration in a position to back off; it has promised America’s Sunni allies it will contain and curtail Iran’s power.
Potential for escalation of the conflict between Tehran and Washington is very real. The brazen acts of the Islamic Revolutionary Guards Corps (IRGC) and its Quds Force—which is tasked with “exporting” Iran’s revolution beyond Iran’s borders—and attempts at testing or tarnishing American power and prestige, risk provoking heavy-handed responses. In the Persian Gulf and Shat al-Arab waterway, for example, the IRGC Navy engages in systematic provocations against the America’s Fifth Fleet, and has previously taken British and American sailors as prisoners of war—releasing them only after extensive use of their photos in humiliating positions in government-controlled media. There are still no reports of Iranian casualties among those killed in America’s recent bombardments of Syrian government and allied Shiite convoys headed to Syria. But the U.S. military response is not likely to deter the IRGC, and it is doubtful if the IRGC leadership would have any other choice but responding in kind in an attempt to avoid losing face in front of the Iranian public.
Such dynamics are not only likely to escalate tensions between Iran and the United States, but could also fuel the vicious cycle of violence for which Tehran is ill-prepared.
There are, however, also a few mitigating factors. Even after the implosion of the Islamic State and its self-proclaimed caliphate, disgruntled Sunnis in Iraq and Syria are likely to rebel against Iran and its Shiite proxies. Regional Sunni powers are just as likely to come to their aid in an attempt to reestablish the regional balance of power. Given such prospects, Tehran is not likely to want an all-out war against Washington. The question is whether Tehran’s leadership—or Washington’s—can prevent it.