Iraq can't be used as a measure how the war on terror is going.
Most of the actual terrorists are outside Iraq, elsewhere in the world.
They are practicing and planning for attacks abroad, against more significant targets.
They cannot be beat by any amount of fightning in Iraq, since they're not in Iraq.
Iraq is full of amateurs to keep up the pressure, so the US cannot withdraw, which means more money poured into Iraq and more political problems within the US. It is just a side show.
Some day the terrorists will strike again abroad, regardless of Iraq and that strike will cause more terror in the west than the whole years terrorist/guerrilla attacks in Iraq. Who gives a crap in the west when a hundred iraqis are killed in a terror attack?
Thats whats the actual terrorists are after, to terrorize the infidels in the west, so they most surely aren't operating in Iraq.