An Afghan police officer turned his gun on NATO troops at a remote checkpoint in southern Afghanistan before dawn Sunday, killing four American service members, according to Afghan and international officials.
It was the third attack by Afghan forces or insurgents disguised in military uniforms against international forces in as many days, killing eight troops in all.
Recent months have seen a string of such insider attacks by Afghan forces against their international counterparts. The killings have imperiled the military partnership between Kabul and NATO, a working relationship that is key to the handover of security responsibilities to Afghan forces as international troops draw down. . .