The core of the strategy is to deny territory to the militants and ultimately defeat them, and to stay out of Syria’s civil war pitting the Syrian government of President Bashar al-Assad, Iran and Russia against domestic opposition forces. The two fights in that country have come into increasingly close proximity in recent months, and there have been clashes.

Military officials from Defense Secretary Jim Mattis on down have emphasized in recent days that they are not looking for a fight with the regime or the Iranians. That has put them at odds with White House officials who have expressed concern about Iranian expansion across a new battlefield in Syria’s southern desert.