It’s easy to criticize President Donald Trump’s decision to launch 59 cruise missiles at a Syrian air base Thursday, April 6.

When Trump’s predecessor, Barack Obama, was deciding whether to use military force against the regime of Syrian dictator Bashar al-Assad in 2013, Trump ridiculed the idea, and he made clear throughout the presidential campaign that he was willing to work with Assad to stamp out Islamic State.

(We’re not going to waste time citing examples of all the people in both parties who have flipped positions on U.S. policy toward Syria now that a different side is in the White House. Just accept that “politics” and “hypocrisy” are synonyms in Washington in 2017.)

Trump acknowledged changing his mind — or, in the poisonous terminology of modern politics, flipflopping — after seeing images of children killed by what the international community (other than Russia and Syria) agrees was a chemical attack by Assad forces.

Many have cited a contradiction between the president’s sudden distress about violence against Syrian children and his efforts since the start of his administration to bar Syrian refugees from settling in the United States.

The point about refugees is not a minor one. We agree that concern for the child victims of Syria’s 6-year-old civil war should extend to those who need a safe place to live and not just to those who are part of the half-million death toll. Perhaps, just as he changed his mind about military action, Trump also will have a change of heart about refugees.

But refugees are a symptom, not the disease. Even if the United States accepted the full 100,000 refugees a year authorized by Obama, millions of people would still be displaced in and around Syria, with more driven from their homes all the time. The only way to solve the refugee crisis is to end the war.

One barrage of cruise missiles won’t accomplish that goal. But it is a clear statement to Assad that if he thinks his actions have no consequences — perhaps because Obama didn’t enforce his own red line about chemical weapons or perhaps because he thinks Trump is under the spell of Russian President Vladimir Putin, Assad’s patron — he is wrong.

Trump’s action was strong, swift and measured. The U.S. Navy didn’t bomb civilians, nor did it target Assad or launch a broad attack on the Syrian military. It struck the one airfield from which the chemical attack originated earlier in the week, and the missile strike didn’t lose its impact by taking place weeks or months later after relentless hemming and hawing.

Sometimes it’s OK to act with controlled outrage in response to what can only be seen as an outrageous action.

What happens next is crucial. The United States must not become another combatant in the Syrian civil war, but we can lay down the international law for Assad. No more chemical weapons. No more barrel bombs. No more slaughter of civilians. Such attacks will be met with swift and, if necessary, escalating responses.

Syria is a disaster that will not be resolved quickly or easily, and the United States has contributed to that catastrophe with an incoherent, inconsistent and indecisive policy since 2011. But one good decision is a solid start.