Crossing the Red Line: Has Al Shayrat opened the door to US intervention in Syria?

On 21 August 2012, former US President Barrack Obama infamously laid down a “red line” against the usage of chemical or biological weapons by the regime of Syrian President, Bashar Al Assad. Throughout the following years, Obama would face repeated criticisms for failing to enforce it, as reports of widespread chemical weapon usage in Syria continued to emerge. Almost five years later, on 4 April 2017 a “red line” was again crossed, as graphic footage emerged from the site of an airstrike in Khan Shaykhun, a town in Syria’s contested Idlib province. They showed high numbers of civilians exhibiting symptoms congruent with exposure to a toxic chemical agent. The scale of the human tragedy became apparent within hours, with over 80 people killed and hundreds requiring urgent medical attention. In the days following the attack, in a dramatic departure from the US’s previous Syria policy, US President Donald Trump unilaterally ordered a military strike using 59 Tomahawk cruise missiles on the Syrian government-controlled Al Shayrat military airbase in Homs province, believed to be the launch point for the Khan Shaykhun attack. The missile strike marked the first direct intentional military action by the US against Assad since the start of the Syrian civil war.

Up until the Al Shayrat missile strike, US military involvement in Syria had exclusively focused on targeting Islamic State (IS) and Al Qaeda-affiliated militants. The closest the US had come to conducting a military intervention against Assad was in August 2013, when a confirmed chemical weapons attack took place in rebel-held territory in Syria’s eastern Ghouta area, in which hundreds of people were killed. Following the Ghouta attack, Obama advocated for a military strike against Assad. However, he also made it clear that his preference was always for a diplomatic solution. When Russia offered to broker a deal which would see Syria turnover its chemical weapons stockpile, the US accepted. 

Aside from the forensic details, the Ghouta and Khan Shaykhun attacks bear striking similarities. As in the Ghouta attack, Assad denied that his forces had employed chemical weapons at Khan Shaykhun, and Syrian military commanders were quick to blame the rebel opposition. Assad’s Russian backers theorised that the incident was the result of an airstrike hitting and dispersingthe contents of a rebel-controlled chemical weapons factory, implying that the opposition had manufactured the chemical agent. However, in contrast to Ghouta, the US response on 7 April was prompt and violent. The 59 cruise missiles hit Al Shayrat while the UN Security Council was still scheduling a vote on a draft resolution demanding an investigation into the Khan Shaykhun incident. 

In large part, the Trump administration’s response was tied to his desire to contrast himself with Obama, describing the 4 April chemical attack itself as “a consequence of the past administration’s weakness and irresolution”. However, the strike on Al Shayrat also served to meet several strategic objectives. Foremost was to provide a disincentive to Assad over any future use of chemical weapons, whilst his conventional forces remained strained. 

On the eve of the chemical attack at Khan Shaykhun, the military balance in Syria had shifted to its most favourable point for the regime since 2011. Russian support for Assad had enabled the Syrian army to consolidate its hold on territory, and even to regain several key areas – including the contested city of Aleppo. Nonetheless, the Syrian army remains overstretched and incapable of carrying out simultaneous offensives on multiple fronts. For instance, in December 2016, the IS launched a surprise assault on the Syrian regime in the central city of Palmyra, when Assad’s forces were predominantly focused on intensifying a campaign to retake Aleppo. The Syrian forces at Palmyra fled, despite support from Russian airstrikes. 

In this context, the tactical impact of the Al Shayrat missile strike is potentially significant. US Secretary of Defence James Mattis stated that the strike destroyed 20 planes, making up about 20 percent of the Syrian government’s operational aircraft – a significant loss for a force hugely reliant on air support to sustain its military edge. However, the US gave Russia advance warning of the strike in order to avoid incurring Russian casualties, and it is likely that some critical Syrian manpower and hardware was as a result removed from the base before the strikes took place. While the figure is therefore likely to be lower than Mattis states, Russian military officials’ claims that only 23 of the 59 missiles actually reached Al Shayrat and only six MiG-23 fighter jets were destroyed, are dubious. Irrespective, the loss of any Syrian air assets carries a heavy price tag for Assad, and is likely to dissuade his forces from employing chemical weapons again. 

Beyond disrupting Assad’s air operations and convincing him of the high costs of any further use of chemical weapons, the bombardment of Al Shayrat was also aimed at driving a wedge between Assad and his international allies, Iran and Russia. In responding to the chemical attack with military means, the Trump administration was asserting that it was willing to take concrete action against Assad, and communicating to Iran and Russia that they should reconsider their support of the Syrian president. 

Instead, the strike elicited the opposite response. Both Russia and Iran closed ranks and vociferously defended Assad from what they described as an act of “aggression against a sovereign state”. Russia subsequently announced that it is speeding up development of the advanced S-500 air defence system for domestic air defence, implying that the system will be deployed to Syria to prevent further similar incidents. The Iranian Foreign Ministry spokesman, Bahram Ghassemi, accused the US of using the “suspicious” chemical attack as a “pretext”, and stated that US actions would benefit “terrorists”. Furthermore, as with previous attempts to muster collective action against Assad within the UN Security Council, when adraft resolution calling for an investigation into the Khan Shaykhun attack was raised on 12 April, Russia exercised its veto power, effectively shielding Assad from any immediate repercussions. 

While the rhetoric emerging from the White House since the strike has been mixed, the overall messaging suggests that a broader US intervention remains distant. Trump has taken great pains to emphasise the overt connection between the missile strike and the chemical attack at Khan Shaykhun – framing it as a specific response to a specific act. Additionally, in the aftermath of the strike, US Secretary of State Rex Tillerson stated that the US military posture towards Assad remains unchanged, and that the US’s first priority in Syria remains to defeat IS. A broader intervention is also likely to lack international backing. While a broad range of countries expressed support for the US strike at Al Shayrat, it was simultaneously condemned by others as a unilateral – and unauthorised – act of aggression. 

With the US unlikely to escalate its response, the lingering effect of these developments on the conflict is likely to be muted. While the US strike sets a precedent for future action against Assad, this is thus far restricted to further instances of chemical weapons usage – which are unlikely to be forthcoming now that Assad is virtually assured of a US military reaction. Outside of this scenario, with the breathing room provided courtesy of Iran and Russia, Assad is unlikely to back down. For Syria, this means a continuation of the day-to-day violence of the past six years, which no “red lines” cover.