When Donald Trump ran for president, he showed no interested in seeking the ouster of Syrian President Bashar al-Assad and fantasized routinely about the idea of working with his most powerful ally and protector, Russia, to defeat ISIS in Syria and Iraq.
"Wouldn't it be nice if we got together with Russia and knocked the hell out of ISIS?" he frequently asked his audience on the campaign trail.
But on Thursday Trump launched 59 tomahawk missiles at one of Assad's airbases — the first direct assault on Assad since Syria's civil war began six years ago — and angered Moscow in the process. Soon after, the Kremlin slammed Trump over the strike, announced that it would bolster Syria's air defenses in response, and suspended a pact in which Russia and the US coordinate their air operations in Syria so as to prevent accidental midair collisions.
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That doesn't bode well for Trump's oft-repeated vision for defeating ISIS. If Trump is bombing Russian President Vladimir Putin's dearest Mideast ally, how can they work together on defeating the group? And if he keeps doing it, will the US end up in two wars instead of one?
The US and Russia don't want to come to blows
Up until Thursday, the US and Russia have generally been guided by the principle that it's not in any of their interests to slide into direct war with each other in Syria. While the US doesn't want Assad in power and has armed and trained Syrian rebels who want to unseat him, it has refrained from attacking him directly.
The US has also held back from hitting Russian forces, and coordinated with their air operations to ensure they don't accidentally collide over Syrian airspace. Syria and Russia have attacked US-backed rebels, but they have not sought to strike at US forces either.
But they aren't just held back by a desire to not slide into war — they also have converging interests in defeating ISIS. The US's chief military objective in Syria is defeating ISIS, mainly by helping train and arm Arab and Kurdish fighters and supporting them with air strikes.
Assad also wants to take down ISIS. While in the past he has actively nurtured the precursors to ISIS — al Qaeda in Iraq — and found ISIS's fighting against his opposition groups to be strategically useful (think "divide and conquer"), he is also ultimately interested in defeating the group, an unruly rival for power in the region.
According to Charles Lister, a senior fellow at the Middle East Institute, Russia's first priority is protecting the Assad regime — its chief proxy force in the region — from rebel forces, but it too wants to take down ISIS and considers unchallenged Islamist extremism in the Middle East to be a threat to its own national security.
Trump's strike on Syria has thrown a wrench into this dynamic. By directly confronting Assad, the US is deviating from a general understanding that the differences between the US, Syria, and Russia shouldn't mean they come to blows against each other, at least directly. It could also upset their shared interests in fighting ISIS.
If this was a one-off attack, things (might) stay the same
Trump's missile strikes seem to have been a one-off measure designed to deter Assad from using chemical weapons. His rhetoric on Thursday evening, which described the strike as intended "to prevent and deter the spread of chemical weapons," suggests as much. The tomahawk missiles were explicit punishment for using gas on civilians, and there seem to be no further strikes planned, though it's hard to know for sure.
If that's the case, what matters most is the way Assad chooses to behave going forward. If he doesn't make use of chemical weapons again, then perhaps we'll see a return to the status quo and the dynamics of conflict in Syria could remain fairly similar to the way they have so far.
Or, maybe, they wouldn't. Any analyst will tell you that Trump is simply impossible to predict.
"Say Assad did get the message and didn't use chemical weapons again. Would they just go back to the way they were? Would Trump just go back and say, 'Now we can go back to focusing on ISIS'? I mean, possibly. I wouldn't rule that out as a possibility," Thomas Wright, director of the Project on International Order and Strategy at the Brookings Institution, told Vox.
"Or will Trump be so outraged with Assad that he won't want to work with him again? We just don't know," he added.
Part of that is because Trump's decision to strike Assad clearly seems to have been based on an emotional, impulsive response to news of the chemical attack. Lister says he's learned from people directly connected to Trump that watching Fox News in the wake of the attack appeared to have a transformative effect on his perception of Assad, and played a critical role in his departure from his earlier stated aversion to directly intervening in the Syrian civil war.
"What we've seen develop in the last week is a realization in Trump's mind that his preconceptions about Syria were false, and that in fact the situation there is so bad and the people who he had considered to either be acceptable — i.e., Assad — or potentially worthy partners — i.e., Russia — are simply not what he thought they were," Lister said.
If it wasn't a one-off attack, things could quickly spiral out of control
There is another scenario, though, in which Assad challenges the US by carrying out chemical attacks on civilians again. Trump would then have to decide if he wants to hold back or retaliate again to make his message of deterrence clear. And if Assad then launches yet another chemical attack, Trump could feel obligated to respond yet again in order to ensure he doesn't look weak.
In a worst-case scenario, Assad continues to do so relentlessly, and Trump decides to escalate the use of force against him dramatically and becomes fully involved in a war against Assad. That would, by extension, become a fight with Putin as well.
That development would fundamentally alter some of the dynamics of the war against ISIS. The US would be fighting on two fronts in Syria, rather than just one. Attention and resources would be spread between the two campaigns, and an increased focus on Assad would mean that the US-led incursions against ISIS would likely slow as a result. The US's relationship with Russia would also plunge to a lower point than it is right now, further damaging Trump's hope of a warming in ties between Washington and Kremlin.
Trump spent much of his time on the campaign trail making clear that he had little interest in getting involved in Assad's affairs and simply wanted to eradicate ISIS alongside anyone who would join the cause.
But Assad's chemical attacks have changed how he thinks about the region, and his strike against Assad has changed how other actors in the region view him. Indeed, the chemical attack may even have affected how Trump views Russia; the US military is looking into whether Moscow had any knowledge of or role in the chemical attack itself.
Trump is learning very quickly that much like health care, Syria policy is far more complicated than he anticipated.
Commentary by Zeeshan Aleem, a foreign affairs staff writer. Follow him on Twitter @ZeeshanAleem.
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