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.

Deft diplomacy will also be necessary to reduce the risks of wider war. It doesn’t help that Trump is undermining the nuclear deal with Iran at the same time as he is ratcheting up the stakes in Syria. One key determinant now is how much Russia is willing to add action to match its relentless campaign of lies and bluster about Syria and chemical weapons. Another is whether Iran, Assad, and Hezbollah are willing to sit on their hands after these strikes. In the past, all three have been willing to refrain from action despite angry promises.

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The problem is the context. Any American action in the Middle East ought to be embedded in a comprehensive, engaged strategy—which is not likely to be forthcoming. Today, we can be sure that America’s significant moves—from proposals to withdraw military assets fighting ISIS in Syria and Iraq, to promises to degrade the capabilities of Bashar al-Assad or limit the reach of Hezbollah or Iran’s Islamic Revolutionary Guard Corps—will land à la carte, increasing the danger of miscalculation and violent, destabilizing escalation.

At stake is how to manage disorder in the Middle East, and more important still, where to draw the line with a resurgent Russia.

Containing rival powers is an art, not a science. Military planners talk about the “escalation ladder” as if it were a chemical equation, but in reality escalation hinges on unpredictable questions of politics, interests, psychology, hard power, and willingness to deploy it.

Obama’s strategy could most simply be understood as a desire to contain regional fires with minimal involvement, while keeping an equal distance from regional antagonists, including Saudi Arabia and Iran, and difficult regional allies including Turkey and Israel. The U.S. got involved in the fight against ISIS, by this logic, with minimal resources and local alliances that it knew couldn’t outlive the immediate counter-terrorism operation.

In the Syrian context, Obama early on made clear that the United States commitment to principles of democracy and human rights would remain primarily rhetorical. Today, the United States has discarded even many of the rhetorical trappings of American exceptionalism. Trump has made clear that he doesn’t apply a moral calculus to superpower behavior. But he’s also expressed personal outrage about Syria’s use of chemical weapons—and he visibly takes umbrage at being personally embarrassed or humiliated.