I put this attack in the same boat as the Fort Hood shooting. Someone you are supposed to trust decided to betray you. What makes it different is that the attack came from a supposed friendly force.
The Afghan government and military hierarchy should be held accountable. This is not the first instance of Afghans stabbing Americans in the back.
There is no reason for American forces to remain in Afghanistan. If a withdrawal does not begin immediately, someone needs to start asking a lot of questions in the Pentagon.