The Russian Air Force, Syrian Arab Army, Lebanese Hezbollah, and Iranian Islamic Revolutionary Guard Corps (IRGC)-trained and led militias have assembled a significant force in Syria. As part of a multi-front campaign to undermine the opposition forces’ 2015 gains, that force aims to recapture Aleppo (Syria’s second largest city). Russia’s new role in targeting the Syrian opposition is fairly clear. But the exact nature of Iran’s apparent escalation on the ground remains something of a mystery, with potentially significant implications.

Iran reportedly has sent as many as 2,000 Iranian and Iranian-backed militia fighters to the front lines in recent weeks. Officially Tehran continues to say its forces in the country are only advisors and not ground troops in a traditional sense. That has been true for Iran’s involvement in the civil war since it began in 2011. Experienced commanders and specialized personnel from the IRGC’s Quds Force, Ground Forces and Basij branches—experts in proxy warfare, counter-insurgency, and paramilitary operations respectively—have rebuilt the Syrian security forces into a hybrid conventional-militia army augmented by Lebanese Hezbollah and other Shia militias from Afghanistan and Iraq. The Iranians, though, are rarely the trigger-pullers maneuvering on the battlefield. Best to let others do the fighting, and the dying.

The new IRGC troops could just be more of the same. Tehran and Moscow certainly need fresh legs to lead and strengthen the Syrian regime’s new push in Aleppo and elsewhere. But reports continue to emerge that these new IRGC forces are also engaged in the fighting directly. The recent rise in death announcements of IRGC and Basij members explicitly linked to their ground forces units shows the Iranian regime is at least more comfortable openly identifying its fallen soldiers, and potentially indicates Tehran is putting more of its own people in harm’s way.

Leaders in Tehran are also hinting about a shift. Foreign Minister Javad Zarif alluded that Iran’s role in Syria has changed, though claimed Iranian military personnel are still advisors. Other senior officials indicated Iran could expand its military presence in Syria if asked by Damascus or Moscow.

Why would Iranian forces in direct combat in Syria matter? First, it would represent an historic development and perhaps a change in military doctrine. For the first time since the Iran-Iraq War of the 1980s, IRGC units could be acting as an expeditionary force rather than the usual advise, train, equip and proxy-build mission. Even if this shift is out of necessity, the rest of the Middle East now must worry about battle hardened Iranian forces willing to fight in the open across borders, rather than only by proxy in the shadows.

Second, it indicates the depth of Tehran’s and Damascus’ problems in mounting a sufficient force to secure defendable Syrian territory. It is reasonable to assume that Iran would rather not expend its elite IRGC fighters, but there may no longer be a choice. This relatively small IRGC deployment could be the test case for a larger escalation if needed.

Third, it may reflect the operational and strategic demands of Russia’s intervention. Operationally, Putin may have insisted on the new Iranian forces to help ensure a victory on the ground before committing his air force. Strategically, Russia is also likely to have different end states than Iran in mind. Russia may be more willing to sacrifice Assad, Damascus, or the emerging Iranian position against Israel in the Golan Heights, if it ensures a settlement that retains Putin’s interests and naval base along the Mediterranean Coast. Tehran’s escalation may be a response to concerns of losing strategic control to Russia, and an effort to ensure Iranian leverage in any negotiations.

What is likely even more concerning to Quds Force Commander Qassem Soleimani and Iranian Supreme Leader Ayatollah Ali Khamenei is whether this new deployment will be enough to satisfy Putin’s expectations and turn the tide for Assad. The IRGC is already in unchartered territory. If the fight in Aleppo and elsewhere stalls for more than a couple of months, who knows what steps Iran take next?

This piece first appeared on AEI's website here.

Image: Creative Commons/Flickr.