National Edition News cover for June 1, 2015 - U.S. bombers hold their fire for lack of good Iraq targets: In this photo taken Tuesday, March 10, 2015, a U.S F-18 fighter refuels at the back of a KC-135 refueling aircraft over Iraq, Tuesday March 10, 2015. Since the bombing campaign began, American warplanes have handled 80 percent of the 2,780 airstrikes carried out as of Tuesday in Iraq and Syria, according to the most recent figures provided by the U.S. military. (AP Photo/Razan Alzayani)