Even a limited and justified effort to contain Syria and its allies carries a risk of escalation. The Trump administration, with its capricious chief executive and broken policy-making process, is ill equipped to forge the sort of complex strategy needed to manage Russia, Syria, Iran, and a Middle East in conflict. Nor has it so far displayed much interest in building the international cooperation necessary to implement such a strategy—although it was a pleasant development that the United States was joined this time by France and the U.K. rather than proceeding unilaterally. However, the considerable drawbacks of the Trump administration don’t give the West a pass when it comes to Syrian use of chemical weapons, and Russia’s belligerent expansionism. Both need to be checked and contained, even considering the additional risks Trump creates.

In order to have any real impact on chemical weapons use, the response needs to be sustained. Every time the regime uses chemical weapons, there needs to be a retaliation, which specifically targets the regime’s chemical-weapons capacity—command and control, delivery mechanisms including aircraft and bases, storage, research, and the like. A political strategy is indispensable as well. Since Russia is the guarantor of the failed 2013 chemical weapons agreement, the West needs to keep Russia on the hook for Syrian President Bashar al-Assad’s use of chemical weapons. The Pentagon chief suggested that these strikes were a one-off, and only time will tell which of Trump’s preferences prevail.