In talking to my friends in the military, some who are serving multiple tours. One is going back to Iraq, after participating in the initial war, another tour during the worst of the violence, and one during the surge. They have said that pre-surge, the military strategy was simply search and destroy. Find the enemy and kill him.
The problem was, they did not take any ground. As soon as they won a battle, they would pack up and leave. What was left of the terrorist groups would re-occupy, rearm, and re-recruit. Two months later we would have to roll in to the same place and replay the bloody mess again. The only ground we owned was various bases and the "green" zone in Baghdad.
Post surge, our strategy was basically the same one conquering armies have used for millenia. Take and hold the ground. It has worked better than the commanders could have wanted, militarilly at least.
Here are some charts:
You can see that violence has picked up just a bit in the last month or so. We got some intelligence that Al-Queda is nearly out for the count, and they have been doing some mischief to let us know they are still around.
And the chart that I care most about:
The surge is working. With this stability, the people are beginning to make money, and the government is slowly starting to work together.