Who are the bad guys?

I was checking the BBC headlines this evening and came across this article delineating who makes up the insurgency in Iraq. Now I thought this was important because way too many people in the US have this image of "THE INSURGENCY" as though there were some monolithic bloc of people in Iraq who hate us and are trying to kill us. (this despite the fact the MOST attacks in Iraq are carried out against other Iraqis.) The BBC article identifies four groups, Al-Queda in Iraq, The Mehdi Army, Saddam loyalists, and the Ansar al Islami.
I think everyone knows who Al-Queda in Iraq is, the face of the foreign fighters, this group is out to make Iraq a fundamentalist Islamic Terrorist state along the lines of the old Afghanistan. Many, if not most, of their attacks are carried out against the Shiite majority in Iraq using the theory that if they can start an internal religious civil war the US will bail out fast.
The Mehdi army, is one of the many Shiite militias that would be big players if that civil war kicks off for real. This is the group that has twice taken up arms against the US openly. It hasn't been decimated and it's leaders killed pretty much for political reason in Iraq. The leader of this group, Moqtada al Sadr, is a politically savvy young man who is playing a dangerous game but seems to be pulling it off. Currently he is, at least verbally, supporting the government and the election process in Iraq. This could change again at any random minute.
The Saddam loyalists are just that, hold outs from the old Baath party and members of the political/military elite that want to be back on top running the show again. We could take them out of the fight by putting them in the government but the rest of the country wouldn't stand for it and, thankfully, we are not so blinded by "real politik" and overeagerness to pull out that we would consider it. This group has already lost the most and has the least to gain by continuing the fight. I personally rather suspect that most of them will eventually flee the country and form some little exile group to hang around in Paris and bitch to the Press and the various international organizations about how persecuted they are. Just like all the other little exile groups hanging out there.
The Ansar al Islami is a bit different situation. This group rose as an opposition group to other Kurdish resistance/rebel/terrorist groups (depend on who you ask) in the north of Iraq. The main groups were primarily interested in an independent Kurdisatn with them in charge. The Ansar was interested in an independent Kurdistan with them in charge that was fundamentalist. I personally am a bit surprised that the BBC is crediting them with this much influence as they were pretty ruthlessly crushed by the US forces allied with the mainline Kurdish forces back in 2003. Here is a good article that explains their situation. Ansar al Islam

Michael Yon, in one of his old posts Battle for Mosul II goes into some detail about the insurgency in the area of Mosul. It is very interesting reading and quite informative about how the factions there operate. He breaks them down as "former Regime elements" (Saddam loyalists) and "extremists" which are all of the Al-Queda in Iraq variety. Mosul is a primarily Sunni tow so the Shiite forces don't have a big presence there and the Kurds are not welcomed either.