What next?

The unexpected cruise missile attack on a Syrian air base in response to the despicable President Bashar al-Assad’s use of chemical weapons against his own people was measured and appropriate. In fact, former Secretary of State Hillary Clinton earlier recommended the same tactic to keep Assad’s air force from getting off the ground to wage chemical warfare on innocents. But few expected Trump to take that course.

This is the America First president, who campaigned on a pledge to not get overly involved in foreign disputes. Yet by taking military action against the Assad regime he may have opened the door to greater U.S. intervention in a civil war in which Russia, which Trump has been accused of being too cozy, is decidedly on the other side. Moscow was quick to denounce the missile strikes launched from two U.S. destroyers in the eastern Mediterranean Sea.

In announcing the missile strikes Thursday night, Trump said: “It is in this vital national security interest of the United States to prevent and deter the spread and use of deadly chemical weapons.” He said years of previous attempts to change Assad’s behavior had all failed.

So, what comes next? Trump has been fighting accusations that his election campaign may have colluded with the Russians to help him win the presidency. But his attack on the Syrian air base is in a sense a rebuke of Russia, which was supposed to have worked out a deal with Assad in 2013 to destroy his chemical weapons arsenal. A Pentagon spokesman says Russian forces in Syria were warned of the imminent missile strikes on the airfield so they could get out of harm’s way.

Sens. John McCain (R.-Ariz.) and Lindsey Graham (R.-S.C.) said Trump should take additional military steps to cripple Assad’s air force. But Trump may not be willing to go that far. After all, early in the week he seemed visibly unmoved by images of the Khan Sheikhoun victims. Trump must consider the Russian response to any U.S. escalation. Next week’s scheduled meeting between Secretary of State Rex Tillerson and Russian President Putin should provide some indication of that.

More importantly, Trump must consider the response of the American public. A wave of sympathy for the gassed victims of the murderous Assad will dissipate like the wind if Americans feel this country is being drawn into another long, indecipherable war in the Mideast.