The Syrian Government is on the verge of total victory in its civil war and is planning for what comes next. But the Syrian regime is still committing atrocities against civilians, and Assad’s jails are overflowing — and it continues to hold at least two American citizens. In the absence of a real United States strategy, Congress has a chance to act.

What can be done? The Trump Administration’s Syria policy is a disaster. After Donald Trump announced the total pullout of US troops in a tweet in December, the defence secretary resigned, as did the official in charge of the anti-Islamic State coalition, who said Trump was giving the terrorist group “new life”.

The national security adviser was publicly rebuked by the President when he tried to set conditions for the withdrawal, and the Secretary of State laughably claims nothing has changed.

“Believe me, there’s no plan for what’s coming next,” Brett McGurk, the former US envoy to the global coalition to fight the Islamic State, told Face the Nation on Sunday. “Right now we do not have a plan.”

Meanwhile, the US military is left to mitigate the damage of Trump’s recklessness while completing a dangerous withdrawal at the same time. The results have already been deadly for US troops. Our partners — not to mention thousands of Syrian civilians — will suffer greatly because of America’s dishonourable actions.

But there is one thing Congress can do: pass legislation to drastically increase sanctions on the Bashar al-Assad regime and those who do business with it. The House passed the Caesar Syrian Civilian Protection Act of 2019 on Tuesday. Now the Senate must follow.

“The world has failed the Syrian people,” House Foreign Affairs Committee chairman Eliot Engel said on the House floor. “Nothing can undo the horrors they have had to endure for nearly eight years. Nothing can bring back those who have been lost. We simply cannot look the other way and allow Assad, Russia and Iran to steamroll over Syria.”

The legislation, which the House passed twice in previous sessions, would require the Trump Administration to sanction anyone who does business with the Syrian Government, its security services or its central bank. The Bill would also sanction anyone involved with Syrian Government-related construction projects or Syria’s state-controlled airline or energy industries.

The Bill is named after “Caesar”, a Syrian military defector who escaped with more than 55,000 images that the FBI has verified as evidence of the Assad regime’s torture and slaying of more than 11,000 civilians held in its custody. The Caesar file represents a fraction of the Assad regime’s crimes against humanity, which include starvation sieges, chemical weapons attacks on civilians and much more.

But the legislation is not just about war crimes. The idea is to give Trump some leverage when dealing with the Assad regime, Russia or even Iran as the Syria tragedy rolls forward. Trump could waive the sanctions on a case-by-case basis under the Bill. If peace negotiations were progressing or regime attacks on civilians ceased, the sanctions could be suspended.

The House passed the Bill by unanimous consent. Even Tulsi Gabbard, the Democratic representative of Hawaii, who voted against a non-binding resolution condemning Assad’s war crimes in 2016, did not object this time around. Today, no one could think this is a “thinly veiled call for no fly zone & war to oust Syrian gov”, as Gabbard said on Twitter at that time.

Trump is getting the United States out of Syria. The President has made it clear he does not believe there is any US national interest there whatsoever.

“We’re talking about sand and death. That’s what we’re talking about,” Trump said at a televised Cabinet meeting on January 2. “We’re not talking about vast wealth. We’re talking about sand and death.”

Nonetheless, there is a broad bipartisan congressional consensus that the United States does have interests in Syria. The fight against Islamic State is not over and cannot be entrusted to Turkey and Russia. If Assad and Iran are allowed to take over existing liberated areas, more death, extremism, refugees and regional instability will surely follow.

Sanctions are not a panacea. It is possible they don’t present enough leverage to force Assad, Russia and Iran to change their strategic calculus. But it is all we have left to try to exert influence there. The European Union sanctioned 11 individuals and five companies on Monday for doing business with the Assad regime. They are trying to enforce the principle that the reconstruction of Syria should begin with political progress and an end to the atrocities.

The White House has issued a statement of support for the Caesar Bill. The Senate should take a break from show votes on the shutdown and vote to remind Assad and the rest of the world that the United States still cares about what happens in Syria. It’s literally the least we can do.

“Passing the Caesar Bill will give renewed hope to an oppressed and downtrodden people that our revolution and justice for our victims is not dead,” Caesar told me. “That our yearning for freedom will continue as long as there are free men and women in the world like the American people and their Congress.”

• Josh Rogin is a columnist for the Global Opinions section of The Washington Post. He writes about foreign policy and national security. Rogin is also a political analyst for CNN. He previously worked for Bloomberg View, the Daily Beast, Foreign Policy, Congressional Quarterly, Federal Computer Week and Japan’s Asahi Shimbun newspaper