Syrian President Bashar Assad’s alleged use of chemical weapons was the predictable result of President Donald Trump’s declaration that he wanted to pull out U.S. troops “very soon” (his advisers persuaded him to at least give them a few more months) and to “let the other people take care of [Syria] now.” And other people did — the Syrian regime with the full support of Russia understands that the United States has no stomach to improve anti-Assad forces’ position on the ground and therefore acts accordingly. Assad saw a green light to do whatever he wanted — and then reportedly barreled ahead.

The Post reports:

“As grisly images emerged, showing bodies of babies in basements and bloodied survivors at hospitals in Eastern Ghouta, Trump made a rare direct criticism of Russian President Vladimir Putin. He said Putin shared blame for the deaths through Russia’s support of Syrian President Bashar Assad.

” ‘President Putin, Russia and Iran are responsible for backing Animal Assad. Big price to pay,’ Trump said in back-to-back tweets. ‘Open area immediately for medical help and verification. Another humanitarian disaster for no reason whatsoever. SICK!’ ”

In a pathetic plea, the State Department implored Putin to cease unqualified support for Assad. (“The United States calls on Russia to end this unmitigated support immediately and work with the international community to prevent further barbaric chemical weapons attacks.”) Putin no doubt got a good laugh over that one. Why should he cease support when the only power with the ability to reshape the battlefield has announced it wants out — as soon as possible?

This is the Obama administration’s policy of paralysis on steroids. If the Obama administration’s restraint only encouraged Russia and Syria to refuse any diplomatic solution, these powers certainly are not going to pull back after the United States declares it wants no troops in the region and, essentially, has no interest in the outcome of the genocidal Syrian civil war.

Trump’s one-off response to Syria’s deployment of sarin gas a year ago filled his apologists with hope that he would depart from President Barack Obama’s policy. See, he understands hard power! See, he knows hard power can be used to leverage diplomacy! In fact, Trump has never had a real policy on Syria. When he expresses a desire to retrench, Assad is emboldened to commit new grisly war crimes. (“Last week was the first anniversary of a sarin attack that killed more than 80 Syrians in the town of Khan Sheikhoun. That occurred shortly after the administration said that it did not believe removing Assad from power was a priority.”) Now, the red line Trump drew against use of chemical weapons has been crossed and he must decide if he wants to do something about it.

Trump in his tweet declares “Big price to pay,” but it is far from clear what he is prepared to do about that. Is the “price” simply another feckless one-day bombing run? Is the price meaningful sanctions against the Russian energy sector, something Trump has so far refused to do?

Sen. Lindsey Graham, R-S.C., tried to make it as simple as possible for the president. On ABC’s “This Week,” he took part in the following exchange:

Graham: “Well, it’s a defining moment in his presidency, because he has challenged Assad in the past not to use chemical weapons. We had a one-and-done missile attack. So Assad is at it again. They see us, our resolve, breaking. They see our determination to stay in Syria waning. And it’s no accident they used chemical weapons.

“But President Trump can reset the table here. To me, I would destroy Assad’s air force. I would create safe zones in Syria where people can come back to their country from the surrounding area and live a better life. Train up Syrians to take on Assad so we can negotiate in Geneva from a position of strength.

“If it becomes a tweet without meaning, then he has hurt himself in North Korea. If he doesn’t follow through and live up to that tweet, he’s going to look weak in the eyes of Russia and Iran. So this is a defining moment, Mr. President. You need to follow through with that tweet. Show a resolve that Obama never did to get this right.”

Martha Raddatz: “And, Sen. Graham, this week also you heard President Trump saying he wanted to pull our troops …”

Graham: “Yes.”

Raddatz: ”… out of Syria. They clarified that somewhat. What do you think about doing that? I know it’s a different fight. It’s against ISIS.”

Graham: “Complete utter disaster to leave before the fight is done. Have we learned nothing when what happens when you leave too soon? We pulled our troops out of Iraq. ISIS came back. But President Trump made a speech in Riyadh, Martha, that was very important. He went to their world and said two things: I stand with you against Iran; and I stand with you to defeat radical Islam.

“If we leave Syria by the mere passage of time, we undercut that policy. ISIS will come back. You will be giving Damascus to the Iranians. They’ll have a land bridge from Tehran to Beirut. Syria will be occupied by Hezbollah, Russia, Iran, a nightmare for our friends in Israel. You’ve got to stick with it. You need a holding force as part of a regional force.

“If Americans are not part of a holding force, ISIS will come back. And there is no strategy by the Trump administration to counter Iranian expansion. And you need a strategy to deal with Iran just as much as ISIS. And the test of that strategy is in Syria.”

This comes at a time when Mike Pompeo has yet to be confirmed as secretary of state and John Bolton begins work as the national security adviser. If, as reports indicate, Bolton is bent on firing a slew of staffers, it will be awfully hard to find expert Middle East hands to figure out a Syria policy this president could abide by. Indeed, Bolton himself, despite hawkishness on Iran, has not voiced much interest in exercising U.S. power in Syria. Like Trump, he seems not to make the connection between U.S. retreat and Iranian regional aggression, or between American fecklessness in the Middle East and Putin’s aggressiveness.

Graham is right. If we do nothing or launch a single bombing operation, Syria — with Iran’s and Russia’s assistance — will keep going, slaughtering civilians, forcing more Syrians to flee the country and hardening their position in Syria.

“The failure to articulate a strategy for Syria after 15 months in office is a signal failure of the Trump administration. It is all well and good to complain, as the president did in his tweet this morning, about the failure to enforce the Obama Red Line, but the Trump administration, with its cruise missile strike last spring, set an implicit red line of its own,” warns former ambassador Eric Edelman. “The failure to enforce it after repeated reports of chemical weapons use in January and February, combined with Trump’s statements about wanting to get out of Syria this past week, arguably set the stage for Saturday’s attack by the regime.” He adds, “We will see what ‘price’ he makes Assad, Putin and Iran pay for these horrific attacks.”

Foes and friends around the world will see if Trump — infamous for overpromising and underdelivering — shows any staying power in Syria. If so, it will be a humiliating turnaround from his declaration of retreat last week but a welcome sign that a coherent Syria policy will be forthcoming.

Jennifer Rubin.

Jennifer Rubin writes the Right Turn blog for The Post, offering reported opinion from a conservative perspective.