Marines and Iraqi Army troops lock down a group of Iraqi Insurgents. After setting up their cordon, they breech the building and start clearing it room by room. They take one casualty in the process.

The thing about close quarters battle in the earliest stages of the Iraq War was that regular line infantry units simply didn't have the tools in their tool-belt that they needed to succeed. The only basic fundamental tools that the average infantryman possessed in 2003 until 2005 was mostly just speed, surprise, and pure violence of action.

So, when you see early videos from the Iraq War like this one, remember that the Marines and Soldiers moving through the building most likely are making up and learning the rules in blood as they go along. It wasn't until after the large scale fighting in places like Fallujah, Ramadi, and Baghdad, that line infantry units started getting regular training in how to conduct close quarters battle drills.

This video is a great example from that time.