President Donald Trump enforced Barack Obama’s porous red line on chemical weapons and in so doing has made it possible, for better or worse, for the US to participate in trying to end the war in Syria–through escalation.

Trump bombs Syrian air base: Cruise missile-ing toward more intervention?

By itself, sending cruise missiles to bomb a Syrian air base will probably not alter the course of the war in the short term. After all, Russia is still backing Syrian leader Bashar al-Assad with air power. Assad has been winning since Russia began bombing a year and a half ago. Iran provides and its Lebanese ally Hezbollah provide troops to help Assad’s army fight.

Now, Trump ought to parlay the intervention into a  move to impel Russia and Iran to consider a national unity government to replace the Assad regime. Such a diplomatic solution would put opposition representatives of Sunni Muslims, the majority in Syria and mainstay of the revolt, in positions of real influence in government. It would also require sidelining radical Islamist groups like ISIS, something Trump, Putin and the Iranian leadership might agree on.

Such a hypothetical move has no chance of working if the cruise missile strikes are just a one-off by Trump, who faced criticism from both Democrats and Republicans for being soft on Syria following the chemical attack on a rebel-held area. If the intervention is more than a feint, then Trump can try to aggressively persuade Russia that current peace talks sponsored by Vladimir Putin ought to diminish Assad’s dominance. The talks must provide a real say in government for Sunni opponents of the regime. Secretary of State Rex Tillerson  is scheduled to visit Moscow next week. Let’s see what he and the Russians say.

Of course, the risk is that Putin, who nurtures a Mr. Tough Guy image like Trump, won’t let this US move go unchallenged. At a minimum, Putin could step up military support for Assad.

Convincing Iran to alter its policy will be even tougher than changing Putin’s mind. Iran’s alliance with Assad is key to Iranian influence in the Middle East and it views any compromise as weakening its hold on Damascus. Tehran wants victory. Only the possibility of Assad losing, or at least getting mired in a never-ending war, may persuade the Islamic Republic to rethink its full support. Or they too, could strike back, maybe by unleashing terror elsewhere.

Anyway, fifty bombs on a Syrian air base is probably not enough to scare off Tehran. Does Trump have more in his arsenal? At least the threat is there.

Trump’s move contrasts starkly with Obama’s policy. Unlike Obama, Trump has decided not to cede direct military activity to the Russians and Iran. Obama’s reluctance to do anything to deter Assad, in particular following a 2013 chemical attack on a Damascus neighborhood, meant the US had no muscle to put behind pleas for a political end to the civil war.

Obama repeatedly sent his Secretary of State John Kerry to Moscow to get the Russians to dump Assad, or at least dilute Assad’s hold on power. The Russians blew him off.

Moreover, the supposed destruction of Assad’s chemical weapons store in 2013, which Putin said he had brokered, apparently didn’t happen, at least not fully. After having said that the use of chemical weapons would be a “red line” Assad ought not cross, Obama backed off. He justified the retreat on the grounds that Putin’s deal with Trump accomplished Washington’s goals. Trump is not going that route.

Now Moscow and Tehran have to take possible Trump interventions into consideration. Maybe not a game changer, but for the first time, Washington has taken a direct military role against Assad. Whether that will speed the end of the war or prolong it is the question.

The domestic benefits of Trump’s bombing.

Russia and Iran oppose strikes.

Newsweek lists some risks.