Mujahideen Tactics in the Soviet-Afghan War - Bennett Park Raiders

Chapter 1, Vignette 4 Page 19
may want to attack the middle or tail of the convoy with the hope that
the convoy commander will not divert a great deal of combat power
back to deal with his attack. If the guerrilla is after supplies, the
middle of the convoy is best if he can isolate a piece of the middle, since
most convoys have a rear guard. In this case, the purpose of the
ambush was to harass, not to capture supplies. The ambush site was
fairly constricted due to the proximity of the river and road to the high
ground, but it still allowed armored vehicles to turn around in the
area. The ambush commander decided to attack toward the rear of the
convoy, but far enough forward to avoid the rear guard.