If they know insurgents are streaming in, can't they be stopped before the all-out attack?
its all a matter of timing: they are waiting for the order from their superiors in Iran, which needs to coordinate this with the Iran/Syria/Hizbullah nuclear attack on Israel and perhaps the simultaneous invasion of S Korea by their N Korean allies...
"If they know insurgents are streaming in, can't they be stopped before the all-out attack?"
Put a wall around baghdad and let them fight it out. Whoever is the winner, we kill.
good point - we know they are "streaming in"? shoot them.