U.S. carriers can’t fly over Afghanistan unless they receive authorization, the Federal Aviation Administration (FAA) said Monday. All U.S. carriers and commercial operators are “prohibited from operating at all altitudes” in the region around Kabul, except for Department of Defense flights, the FAA said. The air authority said the move was made because of “the risk posed by extremist/militant activity, lack of risk mitigation capabilities, and disruptions to air traffic services.” Flights authorized by another U.S. government agency or the FAA can still operate in the restricted airspace. The United States pulled out its last troops from Afghanistan earlier Monday, ending a 20-year war. U.S. troops had been holding the Hamid Karzai International Airport for weeks, enabling the evacuation of tens of thousands of Afghans and thousands of Americans. The Taliban terrorist group took control of the airport shortly after the final American troops left. Americans were told in an Aug. 31 …