Images from the abandoned American post in Nuristan, Afghanistan, show something interesting. Apparently the Taliban obtained a number of American weapons after the Army left the post. Photos show a Taliban with an M-4 carbine with its attached scopes. http://www.nefafoundation.org/miscellaneous/TalibanNuristan2.pdf This is important for two reasons. The first is that it showed that the retreat from this outpost was not in good order. Leaving weapons behind is a sign of disintigration of a unit and a lack good order. Similar events are the American retreat in the Battle of the Bulge and the bugouts in the Korean War. Those cases resulted in a great loss of military equipment, including, most importantly, individual weapons. The import of the loss of individual weapons is that it shows that the soldier involved has lost disipline and cares only for his own life, not that of fellow members of the unit. The unit has disolved and what a soldier fights most for, his fellow soldiers in the smallest unit of the military, the squad or fire team, has broken appart.
What it also may show, and this may be the issue, the more likely issue, is the low quality of the family of M-16 rifle and variants, of which the M-4 is the carbine version of the M-16 assault rifle. The current design of the M-16 family has a mean failure of approximatley 400 rounds. Which basically means after 400 rounds, about 30 minutes of heavy combat, the rifle is likely to fail, either intermitantly or catastrophically. This is caused by its lightweight, fragile construction, and the direct gas impingement system of operation.
It is quite the opposite of the Kalashnikov family of weapons that the Taliban uses, which is sturdy, rugged design, and the more dependable gas piston system of operation. Basically, the Taliban can shot all day, easily overwhelming American units whose basic individual weapons system is just one hour or less away from failure. All thanks to the commie numbers cruncher Robert McNamara.