The main question after strikes on Syria: How does Russia respond?

For President Trump, choosing targets and launching cruise missiles to punish the Syrian regime for using chemical weapons this week may have been a relatively clear-cut decision. The big problem is what comes next.

The military had been preparing options for a strike against President Bashar al-Assad since well before 2013, when the Syrian dictator killed more than 1,000 of his own people in a devastating nerve gas attack.

A chemical attack Tuesday blamed on the Assad regime killed scores of civilians and triggered a response from the Pentagon, which launched approximately 50 cruise missiles at a Syrian military airfield late on Thursday.

[Why these missiles are the most likely option for a strike in Syria]

“The basic questions haven’t changed,” said Phil Gordon, a senior official in the Obama White House who took part in many earlier debates about how to punish Assad. “Is there a set of military strikes that you can use to degrade the Syrians’ ability to deliver chemical weapons and, if you do that, what do they do in response?”The biggest difference between 2013, when President Barack Obama last threatened airstrikes against Assad, and today is that the risks of widening the conflict are much greater.

The initial American war plans to punish Assad in 2013 were aimed largely at his chemical weapons capability, said former U.S. officials involved in those deliberations. A direct strike on the Assad regime’s chemical weapons storage facilities was seen as too risky to civilians, because it would have produced a plume of noxious gas.

[Which chemical weapon was used in Syria? Here’s what investigators know.]

Instead military planners drew up a target list that included Assad’s chemical weapons units and the aircraft and artillery that the regime would need to deliver the ordnance. “The intent was to strike the various chemical weapons units,” said a former U.S. official, who spoke on the condition of anonymity to discuss military planning. “We had postured our intelligence units to give us bomb damage assessments — and if we didn’t get the effect we were looking for, we would have hit them again.”

The biggest difference that Trump and his commanders confront now is the presence of Russian troops on the battlefield and Russian air defense systems that are capable of shooting down U.S. planes. Today, Russian troops are intermingled with Syrian forces, and any strike on a Syrian military target could also produce Russian military casualties.

Retired Gen. John Allen, who coordinated the campaign against the Islamic State in Iraq and Syria during the Obama administration, said that the military strikes could have had a “decisive” impact on the war had they been launched in 2013. He described Obama’s decision not to strike as devastating.

“It is much harder now,” Allen said. “The United States has to ask itself a question: How angry do we want to be on this issue? Are we enraged enough morally that we are ready to take action even with the possibility of dead Russians?”