@ Sufi, @ Wrong (you're not doing your name justice here) : Total agreement.
The rise of Islamist movements in a fairly recent phenomenon in Iraqi history*, and I think their present success is partially due to the fact that Islamists give the disparate resistance forces religious/ideological/philosophical justification for their actions, thus hijacking, as it were, the widespread popular support for legitimate resistance for their own purposes, which is to assert themselves as the main political power in a post-Coalition Iraq.
It is in the Islamists' interest to make the struggle a religious one (which is made all the more easy if your enemy doesn't stop repeating that his God is on his side), and one could argue that it is in the Coalition's interest to appear to be fighting fundamentalism (embodied, as always, in the figure of one top badman, e.g. Zarqawi) while all sorts of devious agendas can be carried out and troop presence maintained even after elections, ostensibly to 'protect democracy'.
This "war" (and it's a "war" because the rules of war are not applied) is self-perpetuating and unwinnable, as is indeed the greater "War on Terror" (like the doomed "War on Drugs"). This is so painfully obvious that one must openly question who the main beneficiaries of this permanent state of "war" really are.
* Iraq was one of the most secular Arab states even before the Baathists took power. It had, for example, one of the most organized, dedicated and long-suffering Communist parties in the whole of the Middle East, as well as a powerful pro-Nasserite Arab Nationalist movement.
All of which doesn't square up with the "haven for Islamic terrorists" theory, of course.
Lastly, may I recommend this
site on Iraq?