Quote Originally Posted by Rank amateur View Post
When we changed to population centric COIN, did we reach a decision point and implement a new critical system/function or were we forced to a culminating point by insurgents?
Be careful on interchanging decisive point and decision point. I don't know if you intentionally did that.

decision point – (DOD) The point in space and time where the commander or staff anticipates making a decision concerning a specific friendly course of action. A decision point is usually associated with a specific target area of interest, and is located in time and space to permit the commander sufficient lead time to engage the adversary in the target area of interest. Decision points may also be associated with the friendly force and the status of ongoing operations. (Army/Marine Corps) An event, area, or point in the battlespace where and when the friendly commander will make a critical decision.
First, COIN is always going to be population centric.

I think in the scenario you point out culminated the HIC phase, though the decision point was before the culmination point, that is, the decision to enter into a sequel plan that began the stability operations and support operations (remember - there were no insurgents in May 2003). The phase culmination point was reached, but I don't think anyone has reverse engineered the culmination point for the entire war, nor do I think it's possible at this time so long as elections, tribes, and another soveriegn nation's security force have a say in it.