Civil defense members prepare to safely detonate cluster bombs in the rebel-held area in Deraa, Syria July 26, 2017. Picture taken July 26, 2017. REUTERS/Alaa al-Faqir

The United States and European powers have accused the Syrian regime of using chemical weapons, most likely chlorine gas, to strike at rebel positions in the town of Douma, near Damascus, on April 7. President Trump has strongly suggested that the US will respond to this attack which killed more than forty and injured hundreds.

Why did Assad use chemical weapons?

Syria’s apparent use of chemical weapons sunk a Russian cease-fire proposal aimed at ending a seven-week military campaign against antigovernment rebels. The Russian proposal would have allowed Jaish al-Islam, an Islamist anti-regime group, to remain in Douma in exchange for relinquishing heavy weapons which it uses to bombard the regime-controlled capital of Damascus. The Syrian government is said to have objected to the proposal, insisting on what has become a standard mode of operation whereby, after siege, starvation, and intense bombardment, rebels and the local population are removed from strategically important areas and transferred elsewhere.

The discord between the two allies is further evidenced by a statement released by the Syrian official news agency on the heels of the report of this chemical attack. The statement stresses that “any negotiations held now are [to be] with the Syrian State exclusively,” not Russia, “after Jaish al-Islam terrorists begged for [the] cessation of military operations launched against them [last] night.”

Syrian president Bashar al-Assad presumably refused what Russia was willing to accept with the intended purpose of ending, once and for all, the threat posed to Damascus, rather than having to accept a weakened rebel force still embedded among a population that remains largely sympathetic to it. His use of chemical weapons, if confirmed, succeeded in achieving this objective. The rebels acquiesced to the transfer of eight thousand of their fighters, along with up to forty thousand civilians, to rebel-held territory adjacent to the Turkish border.

Did Russia green-light the attack?

President Donald Trump is right to criticize his Russian counterpart, this time calling him out by name, for enabling the Syrian regime by providing it with ongoing military and diplomatic support. Yet, there is so far little open-source evidence that Moscow green-lighted the suspected chemical attack. This gives Moscow plausible deniability, particularly given the subsequent divergence in approaches toward an acceptable cease-fire in Douma. Instead of the use of the more lethal sarin gas, which is tightly-controlled by the central government, several units within the Syrian army use chlorine munitions, the source of which is harder to track.

Assad is believed to have used chemical weapons nearly two hundred times since the beginning of the Syrian conflict in 2011, and at least eight times since President Trump took office, including six times in January and February of this year alone. The use of chlorine at a tactical level is fairly common but rarely results in a mass casualty incident like that of April 2017. The high casualty rate reported in the most recent incident may not have been fully calculated, resulting from chlorine munitions landing in closed quarters where dozens of civilians were sheltering.

What are US policy options?

Although President Trump and his National Security Council, chaired by incoming national security advisor John Bolton, are due to decide on a course of action for Syria within the next twenty-four to forty-eight hours, it is highly likely that a US military response will be forthcoming, possibly in partnership with France and other allies. With President Trump having publicly pledged that there will be “a big price to pay” for President Assad’s actions, it is hard to imagine he will back down now.

The US administration’s dilemma, however, will be in figuring out what form and scale of military action is most likely to prove effective. This may be dictated, in part, by whether or not President Trump holds Moscow, or even Tehran, as well as Damascus, accountable. Tomahawk cruise missile strikes similar to those carried out against the Shayrat military airport in April 2017 have clearly failed to induce behavioral change within the Syrian government. A much broader bombing campaign to ground the Syrian air force may be possible, thereby depriving Assad of one of his most valuable military assets given his military’s chronic manpower shortages and inability to sustainably project power. Such a punishing reprisal, nevertheless, risks a more direct confrontation with Russia, which maintains military assets on the ground and an advanced air defense system over Syrian skies.

Can Russia provide a fix?

US and Russian military officials are already in regular communication to “deconflict” over the increasingly crowded Syrian battle space, with such coordination likely to increase ahead of anticipated military action. Given that a purely kinetic approach to the crisis will not offer a meaningful solution to the repeated use of chemical weapons, the United States may again be tempted to entertain Russian diplomatic initiatives regarding Syria. President Trump may be lured in to trying to succeed where President Obama failed in 2013, this time securing President Putin’s assurances against the future use of any chemical weapons, but doing so only after demonstrating military prowess. Such an approach may even provide an opportunity for a broader détente in the otherwise rapidly deteriorating US-Russia relationship.

While this course of action may prove tempting given the lack of viable policy alternatives and Russia’s considerable leverage over the Syrian government, it is not without its risks. As events this week have demonstrated, Russia may have significant influence over President Assad, but it cannot always dictate his actions. Contrary to popular belief, Assad retains a margin of maneuver, sometimes playing his Russian and Iranian patrons off one another.

Has Assad won?

President Assad already succeeded in ending the threat rebels posed to his capital by securing a more favorable cease-fire deal that transfers the rebels and the local population away from Damascus. His Russian allies, although presumably not fully in control of his actions, will be compelled to support him, at least rhetorically and at the United Nations Security Council, in the face of expected US reprisals. Depending on the scale and nature of the military strikes, the Syrian regime may emerge militarily battered and bruised. Nonetheless, it is highly implausible that any such action would threaten Assad’s growing grip on power or significantly roll back his recent military successes. When the bombs stop falling, Assad will remain standing.