WASHINGTON — In December 2009, our commander in chief went to West Point and proclaimed that he would withdraw all U.S. forces from Afghanistan by 2014. Since then, he has proudly emphasized that "We are on a course to end this war responsibly." Now U.S. and NATO troops and loyal Afghan soldiers and police officers are reaping the bitter harvest of the seeds that Barack Obama planted with those words. Over the last 10 days, in five separate incidents, seven American military personnel were killed in what used to be called "green on blue attacks" — where Afghan soldiers or...