Is the real Iraqi army shooting at us because it's personal?

While reading this report describing a training "fiasco" going on in Iraq (by the author of a book with that name) -- with trainers untrained and without knowledge of the language, supported (if at all) by interpreters with limited knowledge of English –- a dynamic of the insurgency that I have not seen reported as such occurred to me. It's personal. We are trying to “train” a new army and police force. Isn’t that because we fired all the old ones, who were trained and experienced, because they were tainted with Ba’athism? So now we have the insurgents who are saying, “Those pretenders have my job,” and they have the training and experience (and a ton of personal, patriotic and religious motivation) to whip the butts of the people we are training – doubly so, of course, when we aren’t really training them because our soldiers with the thankless task of trying to create a new police force and a new army don’t have the resources to do it.

In other words, it looks like Iraq already has a trained police force and army. They are called insurgents. When we leave, won’t they take over the streets in two seconds -- at least the ones not controlled by the Shiite paramiliatary forces -- because they are better trained, more experienced and more motivated than the ones we create to do the fighting we want them to do? How can we possibly train up out of thin air, with no resources, a "third force" that, when we finally leave and allow the government we created to attempt to demonstrate its legitimacy, has a prayer of standing up to the seasoned fighters in the Sunni insurgency and the Shiite armies? So, again, what is it we can we accomplish by “staying the course,” even for a little while? Or adding a bunch of new (and green) American soldiers to be new targets? Tell us, Senator McCain.