President Trump did the right thing, the necessary thing, in striking Syria's Shayrat Air Base in response to the Assad regime's gruesome gas attack on civilians.
In so doing, the president sharply reversed his own past stance and positions his team took just days ago on Syria. Despite his stubborn refusal to criticize Russia's cyberwar on America, moreover, he may finally have grasped the need to display toughness to the Kremlin.
Call it the learning curve of Trump.
The big question now is whether the administration will use this military strike as more than a warning against the use of chemical weapons. The strike gives Trump new leverage to jolt a dying Syrian peace process back to life. But that would require him to play a global role he has previously disdained.
Back in September 2013, when President Barack Obama was agonizing over how to respond to a far larger Syrian gas attack, Donald Trump tweeted: "Do not attack Syria - if you do many very bad things will happen & from that fight the U.S. gets nothing."
Obama agreed. He failed to enforce his own red line, instead crafting a deal with Moscow that supposedly forced Bashar al-Assad to destroy his chemical arsenal. But (as I wrote then), the purpose of enforcing Obama's red line was not to overthrow Assad, something Washington couldn't achieve without boots on the ground. Rather, a strike could have been used to prod Syria and its backers into a serious peace process. That opportunity was lost.
Fast-forward to now. Before the latest gas attack, Trump claimed his only interest in Syria was the defeat of the ISIS caliphate in the east of the country. On my trip to the region last month, Iraqis and Syrians bemoaned the apparent lack of any U.S. political strategy to keep jihadis from emerging again once ISIS was gone.
Only last week, top Trump officials stressed the lack of U.S. interest in removing Assad (which may have emboldened the dictator to think he was invincible).
Then, Assad's stupidity, and the president's visceral reaction to TV scenes of dying children, changed the equation. Whatever the rationale for Trump's sudden reversal, he was correct to do what he did.
That's because, in using sarin gas, the Syrian leader did far worse than violate the 1925 Geneva Convention that bans the use of chemical weapons. (One should note that the U.S. attack occurred on April 6, the 100th anniversary of America's entry into World War I, in which 90,000 allied soldiers were felled by chlorine or mustard gas.) Assad also violated the 2013 deal brokered by Obama and Vladimir Putin that called for Assad to destroy all of his chemical weapons - obviously, he didn't.
Moreover, the Syrian leader flouted U.N. Resolution 2235, which authorizes the use of force if Damascus violates that deal (although Russian veto power makes it impossible for the Security Council to act).
If Assad had been allowed to ignore all these red lines it would have given him carte blanche to continue gassing his own people. It would have demonstrated that the world, and America, had no will to stop the use of chemical weapons elsewhere.
In addition, it would have had two more dangerous consequences. First, it would have demonstrated that American Firster Trump truly had no interest in global leadership on critical issues where U.S. leadership is essential. And second, it would have displayed a continuing Trump unwillingness to treat Putin with the toughness required to convince the Russian that Trump is not an easy mark.
Indeed, it is hard to imagine that the Russians were not complicit in the sarin attack. Russians were stationed at Shayrat Air Base - which is not large - and ought to have known that sarin was stashed there. Perhaps they turned a blind eye because they know that Assad's depleted army lacks the troops to defeat Syrian rebels in their remaining strongholds, so the Kremlin was willing to tolerate the use of gas.
But the repeated Russian denials that Assad was responsible continue the pattern of lies about their actions from the invasion of Ukraine to the hack of the U.S. election. The United States has clear evidence that the attack was launched from Shayrat - U.S. radar spotted the Syrian aircraft that dropped the gas bombs. This is why the American strike has broad backing from U.S. allies around the world.
So Trump had to make clear to the Kremlin that the United States would not tolerate this brazen breach of the 2013 pact. "Trump has to read the Russians the riot act," says Josh Landis, a noted Syria expert at the University of Oklahoma. "He has to get the Russians involved, to ask them what the hell happened."
But the bigger questions - that Secretary of State Rex Tillerson must explore on his scheduled visit to Moscow this week - is whether the Russians are willing to use this strike toward a productive purpose, despite their anti-U.S. bluster. So far Assad has been unwilling to contemplate discussing a political transition that would leave him in power but eventually lead to elections - and Russia had been unwilling to squeeze him.
The message that Russia needs to deliver to Assad, says Andrew Tabler, of the Washington Institute for Near East Policy, is " 'Don't think you can gas your way out.' They must encourage Assad to go down the road to a true political process."
Yet Russia may have no interest in restraining Assad. Even without gas attacks, his barrel-bomb drops on civilians and the resulting refugee flows help Putin's plans to undermine the European Union.
So the test of Trump's learning curve will rest on whether he recognizes the need to hold firm with Putin - and whether he will invest in a diplomatic strategy for Syria that leverages his military action. If he fails on either count, the broader impact of the military strike on Shayrat will be lost.