If anyone has any doubts about why I was gone a month, lets just say that training was involved.
When you go up against the OPFOR at a Combat Training Center (CTC) you get to fight the craftiest fighters on the planet in their respective area. Different CTC's are oriented to different types of organizations (for example heavy mech doesn't go to Fort Polk, but light infantry can go anywhere).
Veterans who got the opportunity to play OPFOR at a CTC (NTC at Fort Irwin, JRTC at Fort Polk, or CMTC at Hohenfels, Germany) have seen pretty much every way to do it wrong, and at least a couple of good examples of doing things well.
In my career I've had 4 CTC rotations, and the last two have been "COIN" oriented for pre-deployment purposes.
Key things I've learned from this latest round of training.
Successful insurgents get the populace on their side. This is a "no duh" comment, but it is somewhat profound. Having the populace on your side means that the BLUFOR is focusing on the populace, instead of focusing on you. This means that for every good deed an insurgent commits, it pays long term benefits in freedom of movement and logistical support.
One of the better tactics I saw enacted was the "Robin Hood" approach to stealing from the haves (government, international charities, big business) and giving to people who don't have whatever it is you stole (food, medicine, fuel, blankets, building materials, whatever). It doesn't matter that the insurgent is making everything worse, people remember what it feels like to have someone fighting for them. Insurgencies aren't about facts and figures, they are about perception and politics.
Now some people will say, "well that's in training, reality is always different." The answer to that is that training never replicates or duplicates reality, but it is the next best thing to being there. In my limited experience the OPFOR did a damn good job of using real world tactics.
One thing to keep in mind is that the Muslim world is different than the West, so the tactics of Muslim insurgents are keyed in to that culture. In a home grown insurgency (ie civil war) the BLUFOR and OPFOR share the same culture, so I would honestly expect the COIN forces to be much more effective in their native country (if they focus on the population to dry up support for the insurgent). Think about the British ability to utterly penetrate the Provisional IRA.
Every war is unique, but it is always good to train on the basics.