U.S. air forces have so far operated under rules of engagement aimed a zero civilian casualty standard that have left three quarters of bombing sorties returning to their bases without dropping a weapon. The French bombardment of Islamic State in Iraq and Syria (ISIS) targets in the wake of the Paris terror attacks has U.S. officials fielding questions about why those targets were not already hit in the air campaign against the terror group, which has lasted for more than a year. One reason, according to Rep. Ryan Zinke (R-Mont.), a retired Navy SEAL commander and Iraq War veteran, is...