Iran’s involvement in Syria’s civil war is the Islamic Republic’s first overt foreign policy intervention in the Middle East and its most enduring.

Without fanfare, the Islamic Republic sent members of the Islamic Revolutionary Guard Corps (IRGC) and its elite Quds Force to other nations, beginning with Lebanon where the Guards helped organize the powerful militia, Hezbollah, in the early 1980s. Iran’s alliance with the Syrian regime, which facilitated Hezbollah’s creation, also dates to these years when Iran found itself internationally isolated, and was engaged in a bloody war with Iraq.

This alliance continues to be vital to Iran’s geopolitical and ideological objectives. Ever since the Arab Spring reached Syria in 2011, Iran has thrown its support behind the beleaguered president, Bashad al-Assad. This continuous support reflects Iran’s estimation of the consequences of Assad’s removal as unacceptable for Iran’s own national security.

Syria has been an integral part of the so called Axis of Resistance against Israel and a major conduit for Iran’s material support to Hezbollah. From a purely geopolitical standpoint, Hezbollah provides Iran asymmetric deterrence to check Israel’s power. Iran and Israel are two middle-sized powers which collaborated under the Shah but have competed for influence in the region since the 1979 revolution.

While Israel possesses the only nuclear arsenal in the region, Iran lacks nuclear deterrence and is also inferior in conventional military terms. Hezbollah, possessed of tens of thousands of rockets and other armaments provided by Iran that could easily strike Israel, offers Iran the ability to retaliate should it come under a serious threat. However, if Assad is removed from power, it is not clear whether a successor regime would be willing to continue to facilitate Iranian arms transfers to Hezbollah. This would weaken Hezbollah and further shift the balance of power in favor of Israel. Therefore, one can argue that Iran’s intervention in Syria is partly aimed at maintaining its power-projection capabilities.  

Iran is also engaged in a de-facto Cold War with Saudi Arabia. From Iran’s perspective, the rise of the group that calls itself the Islamic State (ISIS) and the chaos in Syria and Iraq are partly the results of a plot by Saudi Arabia to destabilize the region and limit Iran’s power. 

Iran believes that if Assad is removed from the scene, the Saudis may try to further weaken Iran by destabilizing the Shi’ite-led government in Baghdad, in effect, encircling Tehran. Therefore, in Iran’s calculations, defense of Syria thwarts Saudi plans to weaken Iran’s status. (Saudi Arabia, in turn, sees Iran’s intervention in Syria, Iraq, Lebanon and Yemen as an effort to encircle the Saudi state.)

Iran is actively supporting efforts to defeat ISIS, which Iran sees as a Saudi surrogate, in Iraq and Syria, by sending its Army Special Forces and IRGC units. It is noteworthy that while ISIS poses no significant military threat to Iran’s large army, Iran is concerned about the possible infiltration of ISIS operatives into its territory. In fact, Ayatollah Ali Khamenei, Iran’s Supreme Leader, has warned that if Iran had not intervened in Syria, it would have to fight ISIS inside Iran. While the danger may have been exaggerated to justify Iran’s intervention in Syria, Iran’s concerns about extremist Sunni Muslim groups in Iranian territory are not unwarranted.  

In addition to geopolitical considerations, Syria is also ideologically important to Iran.  In a Sunni dominated region, Iran is the largest official Shi’ite state, and its government — including to some extent in the days of the Shah — has viewed itself as the protector of Shi’ites throughout the Middle East. The Assad family are Alawites, a secular offshoot of Shi’ite Islam; therefore, it would seem natural for Tehran to support the rulers in Damascus.

If the Islamic Republic gives up on Syria, not only would it have abandoned this traditional policy of protecting Shi’ites, it would also raise questions about its own legitimacy as a theologically-based regime. Iran further does not wish to risk losing Syria to the Sunni-dominated camp in the Middle East, since it could weaken the “Shi’ite Crescent.”  Therefore, even if Assad is to be removed from power, one should expect Iran to fully back another Alawite to replace him even though Sunnis comprise a majority of the Syrian population.

The Islamic Republic has been able to use Shiism and the defense of sacred monuments as a pretext to send “ volunteers “ to Syria. In addition to members of Hezbollah, these fighters come from places as far away as Afghanistan and Pakistan to battle what Iran dubs Takfiris or apostates. As casualties among this force have mounted to more than 1,000, Iran has used the defense of Shi’ite interests as the justification and begun to dub its casualties as Shohaday-e Modafe- Haram, or the Martyrs of the Defense of Holy Shrines. 

Despite these ideological considerations, Iran’s intervention in Syria is largely based on Realpolik calculations. It is evident that Iran has concluded that the ramifications of losing Syria are unacceptable; and therefore, has decided to stand firm behind its longstanding ally. 

But the negative consequences of Iran’s intervention are also apparent and not just limited to Iranian casualties. Once popular among Arabs for backing Hezbollah in its 2006 war with Israel, Iran has now become isolated in much of the Arab world. Iran’s decision to support Houthi rebels in Yemen has further infuriated the Saudis and Emiratis who are drawing closer to Iran’s arch-enemy, Israel, in an effort to contain and push back Iran.

It is conceivable that Iran would end its intervention in Yemen, which is of little strategic importance to the Islamic Republic. But it is hard to imagine that Iran would abandon Assad. Iranians remember that when Saudi Arabia and other Arab countries were financially and logistically supporting Iraq’s war machine against Iran in the 1980s, Syria was the only country in the Middle East that stood by Iran’s side. Iran is now repaying an old debt to Syria’s ruling family.  

Sina Azodi is a former Research Assistant at the Woodrow Wilson International Center for Scholars and a graduate of Elliott School of International Affairs (B.A & MA), George Washington University. He focuses on Iran’s foreign policy and U.S.-Iranian relations.  Follow him on Twitter @azodiac83