Since the conflict between Israel and Hamas broke out on Oct. 7, there has been concern that the regime in Iran might initiate a multiple front attack against Israel via its network of militias in the region—a threat that it has consistently made. Until now, much of the attention has focused on the Lebanon-based Hezbollah, the Islamic Revolutionary Guard Corps’ (IRGC) oldest and deadliest proxy. Yet there is another dimension to Tehran’s arsenal that has garnered less attention: the myriad militia groups it controls in Syria and Iraq.

Following the Oct. 7 attack, Esmail Qaani, the IRGC Quds Force commander responsible for managing the Iranian regime’s militia network, has made multiple trips to Syria to coordinate with the IRGC’s proxies there and in neighboring Iraq. Qaani’s visits have been followed by more than 40 missile or drone strikes by Tehran’s proxies against U.S. forces in Syria and Iraq, with the objective of both testing U.S. redlines and controlling the path of escalation. These attacks have been coupled with multiple reports indicating that the IRGC’s proxies in Syria have begun mobilizing toward the Israeli border. Syrian media has also indicated that Hezbollah’s elite Radwan Unit had arrived in Syria in October and deployed close to Israel.

But perhaps the clearest indication about the integral role of the Syrian front to the IRGC’s multifront escalation against Israel came just a few days ago, on Oct. 22, when Qaani reportedly visited southern Syria and established a new “joint operation room” for the IRGC and its proxies alongside the Golan Heights.

The Iranians will likely carefully calibrate their use of proxies and partners with the progress that Israel makes in its campaign to destroy Hamas in the Gaza Strip. As Israel advances, the intensity of the response by the IRGC’s so-called axis of resistance will increase. This will be especially true if Hamas appears on the verge of being defeated in Gaza. Militias in Iraq and Syria will figure heavily in this response.

Tehran sees the Hamas attacks on Israel as the beginning of a longer confrontation with the latter. In essence, the doctrine that the IRGC has built around this long war seeks to make Israel bleed slowly over a long period of time. As senior IRGC commanders have asserted, “the Palestinian operation is the beginning of the Resistance Axis’ movement to destroy Israel.”

In other words, even when this Hamas-Israel conflict eventually settles down, Tehran is preparing for more escalations, albeit from different fronts—and this is where Syria becomes particularly important.

To understand the nature, purpose, and capabilities of these two understudied and overlooked groups, it is essential to go back to their formation during the Syrian civil war.

The outbreak of the Syrian protests in 2011-12 against the Bashar al-Assad regime would prove to be the most consequential phase in the development of the IRGC’s militia doctrine. Syria had been the backbone of Tehran’s so-called axis of resistance, the main artery of support for Hezbollah, and was critical to the existence of the IRGC’s regional expansionist militancy project. Facing the likely prospect of the fall of the Assad regime, from 2013 onward, the IRGC was be forced to change track in Syria.

The first step toward achieving this would come when Ayatollah Ali Khamenei, the Iran’s supreme leader, would transform the IRGC’s involvement in Syria from preserving Assad to carrying out a Shiite jihad and “defending the holy Shia shrines” that he said were under attack by a “[Gulf] Arab-Zionist-Western” axis.

This call for a Shiite jihad, which was ignored in the West, would enable the regime in Iran to introduce an ideological element to the conflict, centered on extreme antisemitism and sectarianism, to draw on the regime’s ideological influence across the region. For Khamenei and senior IRGC commanders, such as Hossein Hamedani, the poor performance of the Syrian military and other pro-Assad groups was due to their lack of ideological commitment as a fighting force. These groups were viewed as mercenaries that lacked the necessary ideological devotion.

The call for a Shiite jihad was the pretext for the IRGC to construct ideologically compliant militias from scratch. On the spectrum of the IRGC’s proxy assets, IRGC-manufactured militias are the most deadly and are under its full command and control. These groups not only receive military, financial, and logistical support from Tehran, but the IRGC also spends significant time and resources to radicalize all of its recruits to ensure that they are ideologically driven militants rather than simply being paid mercenaries.

By Kasra Aarabi, the director of Islamic Revolutionary Guard Corps research at United Against Nuclear Iran, and Jason M. Brodsky, the policy director at United Against Nuclear Iran and a nonresident scholar at the Middle East Institute.

Members of Iran’s Basij force hold the flags of Iran, Lebanon, and proxy forces including Hezbollah during a rally commemorating Quds Day.

Iran’s Proxies in Syria Move Toward Escalation With Israel