The problem isn't the innate capabilities of one group of people or nation, it's a question of what they are fighting for.
What, democracy, yep its a hard call when you look at our pollies
. So they can't be much different ours.
I think the trick is your not fighting for them, your fighting for those a couple of layers down.
The Iraqis aren't running away because they are born cowards, they are running away because there's nothing worth dying for, and they have no confidence in their commanders, equipment, Government, etc.
There in lies the problem, it takes decades to build cohesiveness and a professional force, unless you have a significant amount of recruits who share the common vision and values.
The problem here is most of the choice fighters are kept in reserve in the various militia. That leaves a population of people who potentially are in it for all sorts of reasons, and dying is not high on the list. Especially when the command chain is possibly corrupt, though that is a problem that is not unusual.