Originally Posted by AdultKing

Vietnam was won by a well organised guerrilla army backed by Soviet and Communist Vietnamese trained armies. The Vietnamese were extremely well trained in things like booby traps, sniper activities, purging villages using fire, flash strikes and rape as a weapon.

The reason America lost was, amongst other things, it thought carpet bombing would act as a viable response to these guerrilla tactics.

In Iraq and Afghanistan the fighters you speak of were assembled groups of well trained forces armed and trained by the USA and USSR in the first place. These forces were not average citizens fighting off oppressors, they were ruthless trained fighters with a fearless disregard for their own safety over their cause.

The average citizens, men included, fleeing Syria have no choice, what does someone with no combat training do ? Throw rocks at tanks ? Duck when a barrel bomb hurtles toward them and their family ?