NATO spokesman Brigadier General Gunter Katz told reporters in Kabul Monday that contrary to Taliban claims, the number of attacks by insurgent infiltrators are in the "single digit."
“So when we talk about the insider threat or some call them again green on blue incidents, we talk about 27 incidents so far in this year and we had 37 people killed in those incidents… And most of these incidents were caused by personal grievances, by stress situation, or by battle fatigue,” said Katz.
This anger management issue is a reason to be cautious in dealing with armed Afghans. It is not a reason walk away and to allow Afghanistan to become an anarchic breeding ground for jihadis who want to attack us at home.
If it makes you feel better, I'm sure that among the Taliban and drug gangs that killings are probably pretty common, too. We just don't hear about it.