In the beginning there was Operation Overlord. Then came Operation Rolling Thunder, Operation Desert Storm and Operation Enduring Freedom.Now the fight against the Islamic State has introduced a new concept into modern warfare. Call it Operation Whack-a-Mole."If we try to do everything ourselves all across the Middle East, all across North Africa, we'll be playing whack-a-mole," the president said Monday afternoon at the end of a Pentagon news conference at which he gave an overview of developments in Syria and Iraq.