“While the U.S. formally ended combat operations in Afghanistan in December 2014, U.S. uniformed troops remain advising the Afghan security forces and engaging in combat,” the study’s author, Boston University Professor Neta Crawford notes. While the study finds that the vast and growing majority of these civilians appear to have been killed by antigovernment forces, Crawford observes that a downward trend in the number of civilians killed by pro-government forces appears to be reversing. Importantly, U.S.