The looming Syrian offensive into Idlib presents a challenge to the United States. If Bashar al-Assad uses chemical weapons against rebels and civilians, as he has done twice so far during the tenure of President Donald Trump, how should the US react? The Khan Shaykhun chemical attack in April, 2017, and the Douma attack one year later both brought about US military action. The 2017 US response was a unilateral Tomahawk missile strike against Shayrat airbase. One year later in April, 2018, the US, Great Britain, and France carried out a series of air and missile strikes against targets in Syria in retaliation for the Syrian government’s use of chemical weapons in Douma. If Assad’s forces chose to employ chemical weapons in Idlib will it provoke another US military action? If so, what shape will it take? More importantly, will it run the risk of provoking a Russian response?
The Pentagon and White House are already weighing these questions, and the Pentagon is starting to examine what military options the US will have available if Assad uses chemical weapons in Idlib. Given the Syrian leader’s track record it’s only prudent for the US to begin planning now. If chemical weapons are used again, the White House will want to move swiftly and decisively.
Unfortunately, Assad may not be able to be dissuaded. Idlib province is the last remaining rebel stronghold in Syria. When it is pacified, it will leave the rebels with just a few isolated pockets of territory. An end to the seven-year old conflict will finally be in sight with Assad’s control of Syria all but guaranteed. International concern that the coming offensive could trigger a humanitarian disaster have done nothing to deter the Syrian government, or its Russian and Iranian backers.
With that in mind, any US threats of military action should Syria use chemical weapons are unlikely to dissuade Assad once hostilities begin in Idlib.