What’s next for Syria? Our view:

Unleashing a cruise missile attack is a proper and proportionate response to Assad’s chemical attacks, but, unfortunately, it probably won’t change much

Given the uncertainties surrounding President Donald Trump’s judgment and most especially his past criticism of U.S. involvement in Syria and the praise he has repeatedly heaped on Russian President Vladimir Putin, few could have predicted the events of recent days: the president’s outrage at the use of chemical weapons against children in Syria, his strong condemnation of Syrian President Bashar Assad and, finally, his decision to order naval ships in the Mediterranean Sea to fire 59 Tomahawak missiles at the airfield from which the chemical weapons attack was allegedly launched on Tuesday. It was a breathtaking foreign policy reversal and a welcome one that was — to no one’s surprise — immediately condemned by the Russian government.

First and foremost, it’s heartening to see the use of chemical weapons is still considered a “red line” that must not be crossed. President Barack Obama sought to enforce that standard and realized, at best, mixed success. With help from Mr. Putin, Mr. Obama sought to remove Mr. Assad’s chemical weapons stockpile in 2013 and, as part of that strategy, abstained from the kind of military strike Mr. Trump unleashed late Thursday. Some weapons were removed, but clearly not all, and Mr. Putin’s influence on the country was ultimately strengthened. Also worth noting was Mr. Trump’s reaction at the time and his urgings on Twitter for Mr. Obama to keep the military out of Syria. One can only hope that despots from Pyongyang to Damascus are paying attention to the new, more morally courageous Mr. Trump.

Second, we’re glad to see that President Trump is capable of a change of heart. One of the president’s more alarming personal traits to emerge during his first three months in office has been his unwillingness to be educated on complex subjects and to recognize when he’s wrong. From the failed health care reform bill to the Muslim ban debacle, the administration is not only unwilling to admit fault, it’s rarely willing to admit to the truth. It is an administration of “alternative facts” that, when confronted by error or misstep, prefers to attack its critics or divert public attention. This week’s chemical attack in northern Syria wasn’t the first by the Assad government nor the worst, but it somehow fundamentally changed the president’s views on President Assad and the region.

And finally —finally — Mr. Trump has demonstrated a willingness to stand up to Mr. Putin. Just how much the cruise missile strike will change their relationship is hard to say. At some level, Mr. Putin can’t be all that happy with the use of chemical weapons in Syria. Never mind that his propaganda machine officially questions whether chemical weapons were used, the effectiveness of the U.S. military strike and even Russia’s decision to suspend an agreement with the U.S. over air space in Syria. The Russian leader likely knows he’s made a pact with the devil to support Mr. Assad in order to protect Russian interests, and it isn’t helping his standing in the world. Moreover, Mr. Putin must be embarrassed that his coup in getting Mr. Assad to give up his chemical weapons was in fact a failure. It may now be possible to drive a wedge between Messrs. Assad and Putin, which would enhance the possibility of a peaceful resolution to the Syrian civil war.

Unfortunately, the U.S. can’t solve the conflict in Syria with a one-and-done attack or even a sustained military response. Surely by now we’ve learned that much about the Middle East and the complexities of the conflict. The next step for Mr. Trump needs to be the articulation of a clear U.S. policy toward Syria and consultation with Congress and Western allies, particularly if further military action is required. Part of that response will be to make clear to the world, Russia included, that Mr. Assad has no future in Syria and that he will eventually be required to stand in judgment for war crimes. And as long as President Trump is feeling compassion for Mr. Assad’s youngest victims, he would also do well to reverse course on Syrian refugees and welcome more of those “beautiful little babies” into the United States instead of working so hard to block their path to safety.