February 21, 2024

IntelBrief: Iran’s Battles are Fought Out in Syria


Bottom Line Up Front

  • Iran’s military presence in Syria enables Tehran to pressure the United States and Israel but also provides targets for military actions against Iran.
  • Since October 7, Iran has increased its reliance on allied militia fighters deployed in Syria in order to avoid exposing senior Islamic Revolutionary Guard Corps (IRGC) commanders to Israeli and U.S. strikes.
  • Israel has intensified its strikes on Lebanese Hezbollah positions in Syria as part of Tel Aviv’s post-October 7 low-level conflict with the group.
  • U.S. officials see targeting IRGC assets in Syria as an alternative to striking facilities in Iran itself.

Syria has been pivotal to Iran’s “forward defense” strategy for decades, helping also advance Tehran’s “unity of fronts” doctrine to surround Israel with hostile, pro-Iranian factions capable of attacking Israel at a time of Iran’s choosing. Even before the October 7-related outbreak of regional conflict, the centrality of Syria to Iran’s strategic objectives has necessitated Iran’s Islamic Revolutionary Guard Corps – Qods Force (IRGC-QF) to deploy an estimated 2000 operatives to Syria for three related but separate missions: (1) advising the depleted Syrian Arab Army (SAA) units that are trying to contain continuing challenges from a wide range of anti-Assad groups, including the Islamic State (IS); (2) coordinating the delivery of Iranian weapons shipments across the border to Lebanese Hezbollah; and (3) directing a range of Syrian and third country militia fighters in eastern Syria to pressure the 900 U.S. military personnel deployed there as part of a global coalition mission to defeat IS. These missions have become even more crucial to Tehran’s regional strategy in the aftermath of the October 7 Hamas assault on Israel.

As the IRGC-QF mission in Syria has expanded to match Tehran’s ambitious goals, Iran’s exposure and vulnerabilities have multiplied. Much of the burden for assisting the Assad regime has fallen to Iran over the past two years as Russia – Iran’s partner in rescuing the Assad regime from defeat from 2013 to 2016 – has had to redeploy assets from Syria to prop up its war effort in Ukraine. Iran’s assumption of more responsibility for securing the Assad regime has caused Tehran to deploy a significant proportion of its IRGC-QF advisers in and around the major Syrian population centers, particularly Damascus. There, Israeli intelligence has proven able to pinpoint the movements of IRGC-QF commanders and the locations of key facilities, such as weapons manufacturing and storage sites, giving the Israelis ample opportunities to strike Iranian assets. Since December, Israeli attacks in and around Damascus city have killed more than a dozen senior IRGC-QF commanders, including a December 25 bombing that killed Sayyed Razi Mousavi, who was responsible for coordinating the military alliance between Syria and Iran. Mousavi had been a close associate of the revered IRGC-QF leader Qasem Soleimani, who was felled by a January 2020 Trump administration strike on his vehicle outside the Baghdad airport. A December 28 Israeli airstrike on the Damascus airport reportedly killed nearly a dozen senior IRGC-QF officials, and a strike last month flattened a Damascus building, killing five IRGC-QF officers, including a general who ran intelligence for the force.

The intensifying Israeli action against Iranian assets in Syria reportedly is causing Iran to retrench its own forces there and to rely more heavily on allied militias. One unnamed regional source told Reuters that IRGC-QF operatives in Syria had left their offices and were staying out of sight, adding: "The Iranians won't abandon Syria, but they reduced their presence and movements to the greatest extent." Several other sources told the news agency that, in order to reduce its vulnerability, the IRGC-QF was delegating the management of some of its operations, in part, to Lebanese Hezbollah. Three of the Reuters sources said the IRGC-QF was once again recruiting Shi'ite fighters from Afghanistan and Pakistan – grouped into units called the Fatemiyoun and Zaynabiyoun brigades, respectively, to deploy to Syria. If true, that activity would represent a repeat of Tehran’s strategy earlier in the Syrian civil war when the IRGC-QF recruited thousands of third-country Shia fighters to help the beleaguered Assad regime combat its domestic opposition.

Iran’s increasing reliance on Lebanese Hezbollah’s easy access to and familiarity with the Syrian battlefield has placed the latter at significant risk. Since October 7, Hezbollah has been in a low-level but gradually escalating conflict with Israel in order to put pressure on and tie down the Israel Defense Forces (IDF), potentially enabling Hamas to survive Israel’s offensive. Israel seems to have discarded an unspoken understanding not to inflict heavy casualties on Hezbollah’s militia fighters inside Syria (Israeli forces also targeted Hezbollah positions in southern Lebanon early this week). Israeli leaders evidently have concluded that Syria is vital to keeping Hezbollah resupplied, thereby hindering Israeli efforts to militarily compel the party to pull its forces off the border with Israel. Israel has been carrying out waves of deadly strikes in Syria against cargo trucks, infrastructure, and operatives involved in distributing Iranian weapons to Hezbollah and other regional allies of Tehran. Israel has repeatedly struck and disabled the airports in Syria's capital, Damascus, and northern Aleppo, which Iran uses to transfer arms to Hezbollah and other regional factions. From October 8 until January 8, the intensified Israeli air campaign killed 19 Hezbollah members in Syria - more than twice the rest of 2023 combined, according to a Reuters count. Among the most significant strikes, an Israeli drone attack on December 8 killed three Hezbollah fighters planning possible operations in northern Israel, and another strike on Quneitra in southern Syria reportedly targeted two Hezbollah fighters responsible for weapons transfers. Four more were killed in late December in a bombing of buildings and trucks being used by Iran-aligned militia groups along Syria's eastern border with Iraq – suggesting Israel’s intelligence and strike reach goes way beyond Damascus and the country’s heavily populated western spine.

And the challenges to Iran’s position in Syria do not only come from Israel. In eastern Syria, Iran’s allies based in Iraq, in particular Kata’ib Hezbollah (KH) and the Nujaba Movement, have sought to pressure U.S. forces to leave the region by attacking them in Iraq and, more recently, Jordan. In the context of the Israel-Hamas war, the groups have escalated their attacks on U.S. forces, striking U.S. bases in Syria, Iraq, and over the border in Jordan on more than 180 occasions since October 17. A January 28 attack on the Tower 22 facility in Jordan killed 3 U.S. military personnel. It prompted a large-scale U.S. counter-strike on IRGC-QF-run compounds in Syria and Iraq, as well as a targeted strike in downtown Baghdad on a KH commander allegedly responsible for the Tower 22 attack. Previous U.S. retaliatory attacks have targeted “facility[ies] in eastern Syria used by Iran's Islamic Revolutionary Guard Corps and affiliated groups,” according to U.S. Defense Department news releases. The Tower 22 attacks, as well as the repeated Iran-backed assaults on U.S. forces in Syria and Iraq, have led many members of the U.S. Congress and former U.S. officials to argue for U.S. retaliation against Iran itself. However, U.S. officials have stated consistently since October 7 that the U.S. “does not want war with Iran,” and attacking IRGC-run installations represents a means of imposing costs on Iran and the IRGC without directly provoking hostilities with the Islamic Republic. Moreover, attacking Iran-linked facilities in Syria does not carry with it the political consequences of striking Iran-backed militias in Iraq – strikes that the Baghdad government insists infringe on Iraqi sovereignty. The United States has no relationship with the Assad regime, whose overthrow U.S. officials would support, and retaliatory or pre-emptive U.S. strikes in Syria breach no diplomatic understanding. It is likely that IRGC-run operations in Syria will increasingly constitute the focus of U.S. operations to deter Iran-backed militias, should they resume their attacks after an apparent pause now two weeks long. U.S. officials say they are hopeful that U.S. retaliatory action has caused the militias in Syria and Iraq, and their Iranian patrons, to stand down on new barrages against U.S. forces – perhaps recognizing U.S. officials are willing to escalate significantly if the attacks on U.S. personnel continue.