YOU DON’T SAY. ‘We’re not in perfect control’: U.S. plans operation against Islamic State in Syria despite obstacles.

The Obama administration is racing to settle questions that could scuttle a planned offensive against the Islamic State in the Syrian city of Raqqa that Defense Secretary Ashton B. Carter has said will begin “within weeks . . . and not many weeks.”

Senior administration officials have attributed the newly described urgency to Raqqa’s symbolic role as the “capital of the caliphate” claimed by the militants and intelligence indicating that it is the center of Islamic State planning for terrorist attacks in Europe and the United States.

But the officials acknowledged a wealth of problems that could derail the offensive, including the need to gather and train additional Syrian forces. More ominously, they cite the explosive dynamics between two allies: Turkey and Syrian Kurdish fighters, who form the bulk of the existing offensive force.

There’s also the little matter of Russia’s no-fly zone of Syrian airspace.