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No matter how President Trump follows through on his promise of a “very tough” response to the Syrian regime's alleged use of chemical weapons, he still has to swallow a tougher reality: When it comes to the brutal war there, his administration is boxed into a corner.

For Trump, who loves “winning,” there's no winning in Syria. But he still has the capacity to make things worse.

Trump can tweet furiously about what an “animal” Syrian President Bashar al-Assad is. He can point fingers, albeit hypocritically, at his predecessor for not doing enough to confront Assad's regime. He can declare mission accomplished in the fight against the Islamic State. And he can threaten Russia, a committed Assad ally, with an incoming fusillade of missiles, as he did on Wednesday morning.

But Trump has neither a plan nor the appetite to stop Assad's brutal consolidation of power and the regime's steady destruction of the remaining pockets of rebellion.

To be fair, the complexity of what has unfolded in Syria has tied far more experienced foreign-policy practitioners in knots. Many members of the Washington establishment spent years clamoring for a sharper strategy to both rein in Assad and help end Syria's ruinous conflict. They criticized the Obama administration for not carrying out airstrikes against the regime, sufficiently bolstering moderate rebels or adhering to its own “red lines” on the use of illicit weapons.

But, given the deep involvement of Russia and Iran on Assad's side, it was never certain that a limited U.S. military intervention would be enough to dislodge Assad from Damascus. The alternative — a full-blown war effort against Assad — was understandably unpalatable. And the United States is not exactly a bystander in Syria: It trained Syrian rebels and provided them with key weaponry in the fight against the regime. And, through its campaign against the Islamic State, it has bombed the country some 13,000 times within the past four years and currently has around 2,000 troops on the ground.

Donald Trump says that his Democratic opponent Hillary Clinton’s strategy to address the war in Syria could lead to World War III. (The Washington Post)

Trump, meanwhile, spoke actively against fomenting regime change on the campaign trail. His administration froze State Department funds intended to help stabilize parts of Syria recovered from the Islamic State. Over the past week, the White House signaled it wanted to withdraw its forces from Syria now that the Islamic State appears to have been routed. Critics argued that Trump was effectively sending a message to Assad and patrons to not worry about the United States shifting the tide of battle against the regime.

Trump promised a quick response to the “atrocious” attack. “It can’t be allowed to happen,” he told reporters. And after the U.N. Security Council failed to take meaningful action on Tuesday, the odds grew of an imminent U.S. (and possibly French) strike on the Assad regime.

If history is any precedent, though, Assad was probably not that concerned. Exactly a year ago, Trump ordered a strike on a Syrian airfield after another regime chemical attack. The raid did nothing to alter the trajectory of the war, and there's no reason another strike would be any more effective. “A few cruise missiles won’t change anything,” The Washington Post's editorial board declared this week.

“A president who says he wants to get the hell out of Syria is not really in a position to threaten the military progress of the regime,” Faysal Itani of the Atlantic Council said to my colleagues. “If Assad has boxed us into a position where we’ve got to throw some missiles at him, it doesn’t really change the picture.”

Emile Hokayem of the International Institute for Strategic Studies, a once-vocal advocate of countering Assad and arming mainstream Syrian rebels, told my colleagues this week that the “time for intervention had passed.” That's a reflection of both a battlefield tilted solidly in Assad's favor and the Trump administration's confused messaging.

“There might be a narrow, self-satisfying strike, but as long as there is no bigger perspective or broader strategy for the whole conflict, it may just fuel escalation without meeting any objective,” Hokayem said.

Moscow bureau chief Anton Troianovski describes Russia’s tensions with the U.S. and how state media are covering the alleged chemical weapons attack in Syria. (Sarah Parnass, Anton Troianovski/The Washington Post)

The risk of such an escalation is real. A Syrian air base that housed Iranian personnel was struck on Monday — apparently by Israel — highlighting how quickly retaliatory measures could morph into a shooting war with Iran. (Of course, that war would have many cheerleaders in Washington, especially if carried out largely in secret by the Israelis.)

Any American attack on Syrian military assets also presents the possibility of conflict with Russia, which retains a significant footprint in Syria and was recently reported to be jamming U.S. drones operating in Syrian airspace. This week, aides to President Vladimir Putin circled the wagons, deeming Trump's new wave of sanctions and promise of action in Syria as the latest signs that Russia faces a new era of “geopolitical solitude” and antagonism from the West. Officials warned of a new “Cuban missile crisis” in the Levant — and the prospect of a much more dangerous conflagration.

“Trump has to understand that we’re going to be talking about the possibility of nuclear escalation if we have a collision of the U.S. and Russian militaries,” Igor Korotchenko, a Russian military scholar and member of the Defense Ministry's public-advisory council, said to my colleague Anton Troianovski. “Everything can happen very quickly, and the situation can spin out of the control of the politicians.”

That fear has helped guarantee Assad's position. But Trump still has to chart a way forward, even if his administration's plan is to simply cut and run after another one-off bombing.

James Dobbins, a former Obama administration diplomat, argued that the United States should condition its withdrawal on a set of practical considerations: It should push its Syrian Kurdish allies to broker some kind of deal with Damascus and get an agreement from Assad that pro-Iranian militias will also leave the country. The prospect of the latter happening may not be as far-fetched as it sounds — Assad, if safely ensconced in power, will probably not want to provoke further Israeli strikes nor seem overly dependent on foreign fighters.

“The best that can be hoped for at this late stage is that post-war Syria is no worse than pre-war Syria,” Dobbins wrote in Al-Monitor.

Some Syrians opposed to Assad are resigned to that fate. As a medical student who endured weeks of airstrikes in the rebel enclave of Eastern Ghouta told my colleagues: “When you know there is no one to support you and when you know that the whole world is going to be silent no matter how many times you have been targeted, your choice will be to say: ‘Okay, stop the killings and I will do whatever you like.' "

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