The fall of the Assad regime signals a major shift in the regional order which Tehran views with unease.
Iran’s foreign policy framework is strategically shaped by the establishment (nezam), with governments acting as executors rather than independent policymakers. This distinction highlights a dual-layered structure: the overarching “big game,” set by the leadership, and the “small game,” carried out by elected governments. This structure becomes most evident in Iran’s regional engagements, particularly its commitment to the Axis of Resistance. Syria, as a cornerstone of this axis, holds a central position in Iran’s geopolitical and military strategies. The Syrian conflict, and particularly the period surrounding Bashar al-Assad’s collapse, illustrates the complex interplay of ideology, national security, and regional influence in Iran’s strategic outlook.
The Islamic Republic’s foreign policy is guided by the establishment’s broader strategic vision. Elected governments under reformist or moderate leadership, such as those of Hashemi Rafsanjani, Mohammad Khatami, and Hassan Rouhani, pursued varying levels of rapprochement with the West without disrupting this overarching policy. However, foreign policy concerning the Axis of Resistance remains a “red line” that cannot be openly criticized or challenged, even by conservative factions. Ambassadors to Axis of Resistance nations—Lebanon, Syria, Iraq, and Yemen—are appointed with significant coordination from the Islamic Revolutionary Guard Corps (IRGC), echoing the practices of the pre-1979 Pahlavi regime in security-sensitive areas like Lebanon and Syria.
Strategic Depth Iran’s Syria Doctrine
The Axis of Resistance remains one of the defining features of Iran’s regional policy, underpinned by its military and ideological commitments. For decades, Iran has pursued a strategy of strategic depth, ensuring that conflicts are pushed beyond its borders and fought through proxy groups. Syria, as part of this strategy, played a critical role by serving as a conduit for military and logistical support to Hezbollah and other allied groups.
Following the U.S. invasion of Iraq in 2003 and the removal of Saddam Hussein, Iran successfully transformed Shia ideology into Shia geopolitics, consolidating its influence in Iraq and building a land bridge stretching from Tehran to the Mediterranean. This development was described as the Shia Crescent in 2004 by King Abdullah II of Jordan, reflecting growing concerns among Sunni Arab states about Iran’s expanding influence.
Syria under Assad emerged as a vital link in this geopolitical network. The survival of Assad’s regime allowed Iran to fortify its influence in the Levant, ensuring a steady flow of arms and resources to Hezbollah. From a military perspective, Syria acted as a buffer zone, shielding Iran from direct confrontation with its adversaries, particularly Israel and the United States. In the wake of the Arab Spring and the subsequent Syrian civil war, Iran’s involvement intensified. Framing its involvement as both a religious obligation—defending Shiite shrines—and a national security necessity, Tehran provided Assad with financial aid, military advisors, and direct combat support through the Islamic Revolutionary Guard Corps (IRGC) and allied militias like the Fatemiyoun Brigade (composed of Afghan fighters) and the Zeynabiyoun (composed of Pakistani fighters). This was viewed as a strategic blend of hard and soft power, showcasing the effectiveness and success of Iran’s regional policies.
However, Iran’s strategic calculus was not solely shaped by regional imperatives but also by broader geopolitical alignments. Tehran viewed its alliance with Russia as essential to counterbalancing Western influence in Syria. Russia’s military involvement in 2015, which shifted the conflict decisively in Assad’s favor for a time, aligned with Iran’s interests and enabled both powers to project influence while challenging U.S. hegemony. The Tehran-Moscow partnership, however, remained transactional, with Russia pursuing its own geopolitical objectives in Syria, often at the expense of Iran’s long-term ambitions.
The Aftermath of Assad’s Collapse
Iran’s traditional deterrence strategy, which relies heavily on proxy groups, has faced substantial setbacks following Hamas’s October 7, 2023, attack on Israel. The subsequent weakening of Hamas and Hezbollah—particularly after the Lebanese ceasefire under UN Resolution 1701, which led to Hezbollah’s disarmament—has severely undermined the Axis of Resistance. Some experts argue that this axis has effectively disintegrated, referring to the current state as a “Resistance without an Axis.”
The fall of Bashar al-Assad represents a significant blow to Iran’s regional strategy, dismantling its hard-won strategic depth and eroding its ability to sustain the Axis of Resistance. The consequences of Assad’s collapse are multi-dimensional, impacting Iran militarily, geopolitically, and domestically.
Strategic and Military Consequences
Assad’s fall has severed Iran’s logistical and military corridor to Hezbollah, a critical pillar of the Axis of Resistance. For decades, Syria functioned as the primary supply route for weapons and support to Hezbollah in Lebanon, enabling the group to maintain its military readiness and deter Israel. Without Assad, Iran faces significant challenges in sustaining its proxy network in the Levant. The collapse of this corridor undermines Iran’s ability to project power in the region and forces Tehran to reconsider its strategy for arming and supporting Hezbollah. From a military perspective, the loss of Syria removes a critical buffer zone, exposing Iran to greater vulnerabilities. The prospect of a fragmented Syria, dominated by rival factions or hostile powers, raises the specter of extremist groups gaining ground, echoing the chaotic post-conflict environments of Iraq and Libya. Iran, which once positioned itself as a stabilizing force in Syria, now confronts the fallout of Assad’s collapse and the resurgence of instability on its doorstep.
Geopolitical and Regional Shifts
The fall of Assad has dealt a significant blow to Iran’s geopolitical ambitions, emboldening its regional rivals and altering the balance of power in the Middle East. The United States, Israel, and Sunni Arab states, particularly Saudi Arabia, view Assad’s collapse as a strategic victory, weakening Iran’s influence and diminishing the viability of the Shia Crescent. Turkey, in particular, has emerged as a key player in the post-Assad landscape, positioning itself to fill the power vacuum and expand its influence in Syria. Ankara’s growing role poses further challenges for Iran, as Turkish-backed factions could reshape the dynamics of the region in ways that undermine Tehran’s interests, as indicated by observers in Iran.
Domestically, Assad’s fall has amplified public scrutiny of Iran’s intervention in Syria. Critics have questioned the rationale for Tehran’s heavy investment—both financial and human—in supporting a regime that ultimately failed to survive. The estimated $50 billion Iran spent on the Syrian conflict, coupled with the deaths of over 5,000 soldiers, has fueled discontent among an already strained population facing economic hardship.
Responses and Future Strategy
In the wake of Assad’s collapse, Iran has sought to redefine its deterrence strategy to compensate for the loss of its regional influence. Prominent Iranian officials, including MP Ahmad Naderi, have called for the development of nuclear weapons as a means of restoring deterrence and ensuring national security. While Tehran is unlikely to test a nuclear device immediately, its focus on missile development, drone technology, and maintaining a “nuclear threshold” status has intensified.
Ayatollah Khamenei, Iran’s Supreme Leader, has also endorsed expanding the country’s missile range, dismissing Western concerns and framing such capabilities as essential to countering Israel and other adversaries. This shift reflects Tehran’s recognition of the need to bolster its defense doctrine in light of the Axis of Resistance’s fragmentation. At the same time, some conservative voices within Iran have sought to justify the country’s reduced support for Assad, particularly in the aftermath of Hamas’s October 7, 2023, attack on Israel. By highlighting Assad’s perceived disloyalty to the Axis of Resistance, these narratives attempt to deflect criticism and reframe Iran’s strategic priorities.
Concluding Remarks
Iran’s presence in the region has its ideological dimension, rooted in Shiism and the aim of countering U.S. influence; however, at its core, there exists a nationalist characteristic that prioritizes protecting Iran’s borders by engaging in conflicts abroad. With the weakening of the Axis of Resistance and the perceived decline of Assad’s role, the focus has shifted back to this nationalist element. Key officials, including the head of parliament, the foreign minister, and the Supreme Leader, have increasingly emphasized that Iran’s presence in Syria was primarily aimed at fighting ISIS and defending Iran. By highlighting the territorial and defensive aspects of their involvement while simultaneously downplaying the religious narrative, Iranian authorities seek to respond to the broader public’s concerns and perceptions
The fall of Bashar al-Assad marks a watershed moment for Iran’s regional strategy and its commitment to the ‘Resistance’ in general. Syria, once a linchpin of Iran’s strategic depth and a vital ally, has become a symbol of Tehran’s diminishing influence and the limits of its regional ambitions. The collapse of Assad’s regime has exposed the question about the vulnerabilities of Iran’s proxy-driven strategy, severed its logistical corridors to Hezbollah, and emboldened its regional rivals. Domestically, the heavy financial and human costs of Iran’s policy have intensified public criticism and forced the leadership to confront the consequences of its policies. In response, Tehran has adopted a more defensive posture, prioritizing missile development, drone capabilities, and nuclear brinkmanship as core elements of its revised defense doctrine.
Ultimately, the fall of Assad underscores the fragility of Iran’s regional strategy and the challenges it faces in a rapidly shifting Middle East. As Tehran grapples with the fallout, its ability to adapt and recalibrate will determine the extent of its future influence in the region. For now, the collapse of Assad represents a turning point in Iran’s decades-long efforts to sustain the Axis of Resistance amidst growing internal and external pressures.
