The new United Nations report on civilian casualties in Afghanistan shows that the U.S. strategy in Afghanistan is failing, even according to the military’s own doctrine. According to COIN theory, if you can’t prevent your own side from killing civilians, and you can’t offer credible assurances of security to the population, you lose. And, guess what? Judged by its own standards, the U.S. military is losing. It’s time to end this mission.