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The impact of the Iranian threat in the Middle East on US Foreign Policy in Syria

Connie Farrell, Isaac Greenman, Dulcie Heyes, Marco Parks, Antonios Stavropoulos, CENTCOM March 1, 2021

US Air Force conducting strikes in Syria[1]

The success of the Biden Administration’s foreign policy in Syria is largely influenced by Iran. US airstrikes on Iran-backed facilities in Syria on February 25, 2021, underscore the reality that the far-reaching Iranian presence in the Middle East will be an important barrier to achieving US interests in Syria. Meanwhile, how the American strategy in Syria is conducted will equally dictate its ability to revive the Joint Comprehensive Plan of Action (JCPOA) talks with Iran; this would call for the easing of the economic sanctions against Iran and in return, Iran would minimize the levels of uranium enrichment and its nuclear research program while being subject to an inspection regime. In this context of intertwined challenges, the Iranian threat to US foreign policy in Syria has two main implications: Biden may double-down on airstrikes and continue to stymie Iran’s influence in Syria and Iraq with military power, communicating to Iran that it cannot continue its alliance-making and has no choice but to negotiate. Alternatively, Biden’s bombing strategy may be revised downwards in hopes of thawing relations with Iran and getting a new JCPOA on the negotiating table. Ultimately, the new US administration needs to be aware that the conditions in which it sets its new Middle East policy are far different from what they were under Obama. Iranian nuclear capabilities are more developed and regime stability in Syria is more consolidated now that the threat of ISIS is reduced. Navigating this climate of evolving conditions will take strategic foresight and the return of concerted diplomatic efforts.

In recent years, US policy has done little to mitigate the conflict in Syria or promote long-term peace and does not seek to restore the country's stability with a regime change. The US foreign policy toward Syria under the Trump and Obama administrations may be described as the utilization of smart power with limited engagement based on cooperation with regional and international actors–or realpolitik. Firstly, even though the US does not intend to resolve the Syrian Civil War with a deep and intensive military engagement, it instead champions a political settlement in Syria under the United Nations Security Council Resolution 2254 calling for a ceasefire between the Syrian government and the opposition forces.[2] The US likely fears becoming embroiled in a military quagmire akin to Afghanistan or pressure to lead post-war rebuilding efforts as in Iraq. Yet, the consequence of this in Syria has been a proclivity for missile strikes which, although may eliminate targeted terrorist cells or militias, nevertheless have a devastating impact on Syrian infrastructure, healthcare, and security. The US attempts to redress this through its humanitarian response and has significantly supported emergency food assistance, shelters, drinking water, medical care, and other humanitarian relief activities by providing an overall $12.2 billion in humanitarian assistance.[3] Although this assistance is desperately needed, the US’s fear of long-term commitment to stability in Syria has ensured long-term insecurity—essentially using humanitarian donations as a band-aid for the ongoing suffering of millions of Syrians without addressing the underlying root causes for the crises.

Secondly, the US has had a crucial role in the ousting of ISIS from numerous territories in Syria since 2014. The US’s ongoing commitment to countering ISIS reflects the fact that the group still constitutes a domestic security issue for the US, thus it pledges to protect US home soil and its citizens from ISIS attacks and radicalization. To this end, the US has allocated funding, provided logistical support and training for the local forces, the Syrian Democratic Forces (SDF) and its Kurdish Syrian People’s Protection Units (YPG), to contain ISIS without the need for a full-scale US deployment.[4] Furthermore, aiming to accommodate US strategic interests and curb the role of Iran and its affiliates in Syria, the US has engaged to protect its most important ally in the region, Israel, which is threatened by Iran’s military entrenchment and logistical support in Syria. It can be argued also that as long as Iranian military and backed forces are deployed in the country, the US presence may be regarded as a deterrence to Iran diminishing its influence on the ground.[5] Lastly, the Biden Administration has repeatedly and openly expressed its interest in resuming dialogue with Iran and it is not afraid to facilitate diplomacy through soft or hard power.[6]Hence, the airstrikes conducted by US President Joe Biden against the Iran-backed militias in Syria on February 25, 2021, have a two-fold purpose. The strikes are designed to be interpreted as a warning sign toward Iran by setting the boundaries for the Iranian proxies as well as push Iran to open the negotiations for the return to the JCPOA.

Iran’s proxy influence in Syria and the greater Middle East intends to establish a ‘Shi’a crescent’ to export the Islamic revolution doctrine, pursue regional dominance, and expel the US and Israel from the region.[7] By funding loyal proxies, Iran can expand and entrench an influential force that, when the opportunity arises, can take control of the given country. This is found throughout the region with terrorist organizations such as Hezbollah in Lebanon, the Houthis in Yemen, Hamas in Palestine, and the Popular Mobilization Forces (PMF) in Iraq. Tehran’s opportunistic approach and its efficacy are evident with each of these militias. In Lebanon, Hezbollah has exploited security risks, including a spiraling economy, weak governance, and destabilizing spillover from the Syrian Civil War; currently, Hezbollah asserts its influence across all branches of the Lebanese government, with an increasing proclivity for political repression.[8] Other examples of opportunism are observed in Yemen and Iraq in which the US has pursued an initiative that weakens Iran’s enemy (Sadham Hussain in Iraq and Saudi Arabia in Yemen), thus providing Iran with an exploitable opening. These proxy initiatives have served as a cost-effective method for Iran to expand its dominion without declaring war or jeopardizing as many Iranian lives.

In Syria, since the beginning of the war in 2011, Iran has pursued proxy initiatives to integrate local Iranian militias into Assad’s military, thus giving them legal standing and an umbrella of protection from Israeli or US airstrikes.[9] However, with a decrease in military operations in Syria, Iran found new ways to enhance its influence in different Syrian provinces—some of which include infiltrating Syrian society and strengthening its relations with Syrian businessmen.[10] Iran has opportunistically exploited the widespread hardship faced by local Syrians by recruiting Assad regime soldiers into its militias rather than embedding Iranian militia into existing regime forces. The Fatemiyoun Brigade militia, an Iran-funded and trained Afghan Shia militia established to fight on the side of the Syrian government, offers appealing salaries that are seen as an incredible economic opportunity for fighters struggling to feed their families due to the economic crisis. This shows an evolution in the role of Iranian proxies in Syria to pursue a prolonged approach to infiltrating Syrian society, securing military dominance, and establishing a key piece in its vision of a ‘Shi’a crescent.’ Given that Syria is its neighbor, Iran’s long-term approach is logical and it shows that Iran is willing to commit the time and funding to rebuild the war-torn country in a fashion favorable to its interests.

Iran’s success in infiltrating the Syrian regime’s security apparatus and society poses a threat to US foreign policy interests in Syria. The US must also consider the threat Iran poses to US allies, namely Israel and Saudi Arabia, who share the fear of Tehran’s growing regional strength. Given these threats in Syria in addition to nuclear issues, Iran has quickly proved to be one of the Biden administration's top foreign policy concerns. Therefore, the urgency that is needed to address Iran will likely dictate or at least heavily influence US foreign policy in Syria and the greater Middle East. As such, if the US were to take action in aiding Lebanon’s political and economic crisis, it will likely attempt to prevent Hezbollah (and thus Iran) from reaping benefits. By the same token, a US policy or military initiative in Syria will be formulated in a way that acknowledges and responds to both Iran’s regional and nuclear threat.

Targeting Iran-backed militias in Syria like Hezbollah or Liwa Fatemiyoun may come in the form of direct military force or using a tool in Biden’s diplomatic toolbox. Most recently, the US Military’s approach in Syria has explicitly targeted Iran: on February 25, 2021, the US carried out airstrikes in eastern Syria directly against Iran-backed militias responsible for recent attacks against American personnel in Iraq.[11] The Pentagon stated that they “acted in a deliberate manner [to punish the perpetrators] and aimed to de-escalate the overall situation in both eastern Syria and Iraq,” thus showing that Biden is still seeking to mitigate hostilities with Iran and renew talks on a nuclear deal.[12] This is in contrast to the inflammatory dialogue espoused by the Trump administration following similar strikes on Iranian militias, which only exacerbated tensions and ensured more attacks. Thursday’s airstrikes seemed almost like a replay of US airstrikes in January 2020 after protesters stormed the US embassy, in which Trump escalated tensions by exacting a fatal strike on Iranian general Qassem Soleimani and other high-ranking officials.[13] In the ensuing days, the Middle East seemed on the brink of a US-Iran war.[14] Biden’s handling of Thursday’s airstrikes seems to be a refutation of Trump’s previous inflammatory approach and illustrates the restrained and calibrated policy that Biden will likely take—the occurrence of Iranian diplomatic or military retaliation in the coming months will determine this strategy’s efficacy. Generally, there is a high probability that President Biden, as Commander in Chief, will infrequently pursue military initiatives in Syria due to these attacks’ tendency to elevate tensions, minimizing diplomatic opportunities and catalyzing costly retaliation; thus avoiding a repeat of last year’s escalation and keeping the option of a return to JCPOA talks open by not alienating Iran.

The diplomatic foreign policy that President Biden may employ in Syria will also be influenced in part by Iran’s proxy and governmental infiltration in the conflict. The Biden Administration can broaden its diplomatic effort to constrain Assad and his backers who exacerbate the conflict by rallying the international community’s support and participation. The US could organize a diplomatic bulwark against Iran and Russia as the most influential interveners, specifically targeting the methods they use to exacerbate the conflict—for example, limiting the supply of monetary funding and weaponry/manpower to Assad and Iranian-proxies via a comprehensive arms embargo. While Biden can employ economic tools like sanctions unilaterally, an organized effort to impose austere economic repercussions on the belligerents would almost certainly be more effective in constraining Assad and isolating him from the Iranian military and monetary support. The diplomatic plan of action for the Syrian Civil War would require a concerted effort, in which Iran’s intervening influence is targeted. Given that President Biden’s largest focus in the Middle East is on bringing Iran back into compliance with the JCPOA, Biden is likely to refrain from large-scale diplomatic initiatives in Syria until US-Iran tensions abate.

The Biden administration’s two F-15E strikes on the Iran-backed facilities in Syria underscore a new reality that Iran’s sphere of influence in Syria is alive and well, extending to places other than Iraq and Yemen. Meanwhile, Biden’s new policy for the Middle East needs to be aware that the conditions in which the US will seek to negotiate a JCPOA are not the same as they were under the Obama administration. Advances in Iranian nuclear capability paired with a more stable Syria give more leverage to the Iranians to follow their national interest without compromise. The problem at hand is exacerbated by the simple fact that Iran does not deem the US trustworthy after it backed out of its deal under Donald Trump. As the US seeks to mitigate the Iranian threat by banking on the JCPOA as the cornerstone of its Middle East policy, the success of its policy on Syria will largely dictate its capacity to rebuild trust with Iran and bring it to the table. [15]

With that in mind, American policy in Syria will have one of two potential impacts on the relations with Iran. First, although unlikely as aforementioned, Biden has the option to double-down on airstrikes and continue to stymie Iran’s influence in Syria and Iraq with military power, communicating to Iran that it cannot continue its alliance-making and has no choice but to negotiate. This impact scenario is contingent on the supposition that Iran can be backed into talks with enough military force and that it will reach a breaking point. It also supposes Biden can continue bombing militia facilities with relatively low disapprobation from public opinion. This impact scenario is unlikely because the cost-benefit ratio of repeated strikes on Syria is too low and still does not guarantee Iran will fall in line. So far, the strikes have provoked backlash to steer Iran further away from renewed talks. Alternatively, Biden’s show of force will likely have to cease (or be undertaken more conservatively) if he wants to bring Iran back to the negotiating table on the JCPOA. With this in mind, and considering the flurry of bi-partisan condemnations Biden has faced in Washington, it is likely his new policy in Syria will be revised downwards. In this case, Iran will feel more empowered and we can expect more militia funding as the US recedes.

There is a very valid concern that the US preoccupation with mitigating the Iranian nuclear threat may see its foreign policy in Syria sacrificed in exchange for an Iranian nuclear deal. However, in reality, such a policy– which had previously been adopted by President Obama– simply perpetuates instability in Syria and prolongs security and humanitarian crises. Rather than trade-off Syrian security for an Iranian nuclear deal, the US should instead acknowledge the central importance of Syria to the Iranian foreign policy; particularly through the Iran-Iraq-Syria-Lebanon landbridge or ‘Shi’a Crescent’ which offers Iran a strategic route through which to transfer weapons and fighters. As Middle East experts Aaron Zelin and Oula Alrifai have stated, Washington should act under the assumption that “Syria is the fulcrum of Iran’s regional policy, so pursuing a more active, adroit US policy there can create additional leverage against Tehran.”[16] Although such leverage may create a power dynamic that encourages Iran to come to the negotiating table once again, by agreeing to depart from its Syrian foreign policy in exchange for Iran’s engagement in a nuclear agreement, the US undermines the myriad threats Iran poses regionally beyond its growing nuclear capabilities; it also assumes Iranian compliance with the JCPOA if, or when, it is resumed. Thus, a strategy that prioritizes both Iranian nuclear deterrence and targets the growing influence of proxy militias in the region would if successful, foster more long-term peace and stability rather than short-term, self-interested maneuvers.

There is a risk that the threat of Iranian proxies may overshadow security concerns associated with ISIS resurgence in Syria and Iraq. Furthermore, the geopolitical impact of Iran in the region may also undermine efforts to counter a potential ISIS comeback by creating fragility between the US and Iraqi governments and military forces–two key allies in the coalition to defeat ISIS. President Biden has inherited this fraught relationship which had been exacerbated by the policies of his predecessor. In response to perceived inactivity on the part of Iraq to the Iranian-backed militia strikes on US forces in Baghdad and Erbil, President Trump had threatened to entirely withdraw from Iraq and in doing so leave Iraq and Syria incredibly vulnerable to ISIS resurgence.[17] Though US presence in Iraq was reduced, complete withdrawal was avoided. Nevertheless, this demonstrates how delicate the US-Iraq and Iraq-Iran relations are.

The fragility of these relationships has more recently been demonstrated following US airstrikes on Iranian-backed militias on February 25 when US officials quickly backtracked on a statement claiming that Iraqi forces had supported the operation with intelligence.[18] By implicating Iraq in strikes against Iranian proxies, (even those conducted on Syrian soil) the US puts Iraq in an uncomfortable position with its neighbor Iran, particularly since PMF paramilitary factions are heavily embedded within the Iraqi army. There is a high probability that continued US targeting of Iranian proxies in Syria will see Iraq forced to abandon its careful balancing act between US and Iranian support in favor of a partnership of necessity with Iran, which remains to be a major threat on its doorstep. This outcome may jeopardize the coalition to fight ISIS by limiting intelligence sharing and collaborative operations between Iraq and US militaries, thus further compounding the already complex security landscape in the region.

The foreign policy approach pursued under the Biden Administration with regards to Iran will have cascading effects across the entire CENTCOM region. As mentioned previously, this foreign policy will likely involve addressing the threat by targeting Iranian proxies across the region but particularly in Syria. As was demonstrated in the March 3, 2021 attack on Ain al-Asad military base in Iraq, which houses US troops, retaliation by Iranian-backed militias is almost certain. Beyond Iraq, there is a high likelihood of retaliatory attacks against US interests and US allies by Iranian-backed groups such as Hezbollah, Hamas, and the Houthis across the region.

Given the high probability of this threat, there are already mitigations in place to limit the risks posed by these groups. For instance, Israel, a significant ally of the US, has applied two main counterterrorism strategies in the past: one targeting senior leadership within Hezbollah and Hamas, while the other strategy focused on diminishing popular support for Hezbollah.[19] Israeli counterterrorism forces were successful with regards to the first strategy in the sense that they deterred the Iranian proxy groups’ capacity to attack through a series of tactical airstrikes on military bases and weapons caches in Syria.[20] However, this strategy was also conflicting in the sense that it inspired violence and diminished prospects for peace. The second strategy enforced has been largely unsuccessful; punishing the Lebanese populace in response to Hezbollah attacks proved to backfire and counter Israeli interests as this only increased Lebanese support for the Iranian proxy group. Hezbollah has been a long-time ally of the Ba’ath government of Syria henceforth, official Syrian government counterterrorism initiatives against Hezbollah are nonexistent. Free Syrian Army groups have launched multiple offensives targeting Hezbollah strongholds, military checkpoints held by Hezbollah, as well as weapons shipments.[21] Although the US has not been as offensive in its counterterrorism efforts against Hezbollah specifically, they have targeted key financial figures supporting the proxy group and imposed a series of sanctions against Tehran, thus demonstrating an inclination for diplomatic efforts as opposed to hard counterterrorism initiatives.

Israel’s continuation of consistent counterterrorism strikes on Iranian groups in Syria–by targeting supply chains, weapons caches, communications, and underground networks of tunnels and bunkers– will be critical in countering the ongoing threat they pose. It would allow the US to carry out minimal deterrent airstrikes against Iranian militias, whilst pursuing more diplomatic efforts with Iran to reach a nuclear agreement favorable to all parties. This hard, Israeli militarized approach on the one hand and the softer, more balanced US diplomatic approach on the other, could function as a multilateral foreign policy towards Iran that addresses both the threat of nuclear armament as well as regional expansion. Such a strategy would circumvent US aversion to a more heavy-handed militarized approach for fear of jeopardizing JCPOA negotiations, yet allow the Biden Administration to assert itself as a stabilizing entity in the region which holds all countries accountable for their actions, but in a measured, less inflammatory manner.

The Counterterrorism Group (CTG) anticipates that a cycle of retaliatory violence between the US and Iranian proxies is likely to precede any potential diplomatic efforts. Therefore, we recommend that any US personnel in the CENTCOM region, in particular Iraq, Lebanon, and Yemen, should remain vigilant and increase security measures around high-risk locations including, but not limited to, US embassies and military bases. The CENTCOM Team is also working closely with all CTG regional teams to anticipate and mitigate threats beyond the CENTCOM region given that Iranian militias have a history of targeting US interests wherever security vulnerabilities may exist. CTG endeavors to support all efforts which would bring lasting stability and security to Syria and the CENTCOM region and we will therefore continue to monitor all threats– from both terrorist and state actors– which seek to compromise this goal.

________________________________________________________________________ The Counterterrorism Group (CTG)

[2] Searching for Solutions in Syria: The Trump Administration’s Strategy, U.S. Embassy in Syria, May 2019

[3] U.S. Relations With Syria, U.S. Department of State, January 2021

[4] U.S. funding of Syrian YPG militia will impact Turkey's decisions: Erdogan, Reuters, February 2018

[5] U.S. Policy Toward Syria: Part I Testimony before the House Foreign Affairs Subcommittee on the Middle East and North Africa, United States Institute of Peace, September 2018

[6] Decision time soon for Biden on Iran nuclear deal, France24, February 2021

[7] The Emerging Shia Crescent Symposium: Implications for U.S. Policy in the Middle East, CFR, 2006 East

[8] What Is Hezbollah?, Council of Foreign Relations, September 2020

[9] Factbox: Iranian influence and presence in Syria, Atlantic Council, November 2020

[10] Ibid.

[11] U.S. Airstrikes in Syria Target Iran-Backed Militias That Rocketed American Troops in Iraq, The New York Times, February 2021

[12] US carries out airstrikes against Iranian-backed militia facilities in Syria, Oklahoma News 4, February 2021

[13] Qasem Soleimani: Strike was to 'stop war', says Trump, BBC, January 2020, East-50989745

[14] How Months of Miscalculation Led the U.S. and Iran to the Brink of War, The New York Times, February 2020,

[16] Assad Is Giving Biden Every Reason to Prioritize Syria, The Washington Institute for Near East Policy, March 2021

[17] Trump administration warns Iraq it plans to shut U.S. Embassy in Baghdad after rocket attacks, NBC, September 2020

[19] U.S. Counterterrorism Policy and Hezbollah’s Resilience, Georgetown Security Studies, December 2013,

[20] Syria war: Suspected Israeli strikes on Iran-linked targets 'kill dozens', BBC, January 2021, East-55646298

[21] Ibid.



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