There is a contradiction in the film.  The plot revolves around buying captured Soviet weaponry off Israel and routing it via Pakistan to the Mujahedin - so the Soviets could not blame the US for interfering in their "sphere of Influence".  However later in the film the Mujahedin appear to be using stingers - or perhaps the Soviet weaponry looks very similar.  It's possible Stingers are even mentioned in the commentary later on - I can't remember.

Index of Frank's Diaries