The Institute for the Study of War has released a 30 page report on the summer offensive in Diyala:

It’s a detailed report on three large scale military operations, Fardh al Qanoon, Phantom Thunder, and Phantom Strike, which “decreased violence in Iraq dramatically after June 2007 by driving enemy groups from their safe havens.” 

I’m only halfway through it but it’s an important read if you want to understand how our forces reduced the violence in Iraq’s most violent province.

The conclusions of the report, as summarized here, give a good indication at how brilliant our military performed during these operations:

• The offensive operations in Diyala succeeded because they were designed from beginning to end with the goal of establishing stable security in the region, not of transitioning to Iraqi control (the aim of operations in 2006).

• Kinetic operations during Phantom Thunder and Phantom Strike separated the insurgents from the local populations, while defending the population from retaliation and reinfiltration by enemy groups.

• At the same time, non-kinetic operations to promote economic and political development, in conjunction with the tribal reconciliation movements and concerned local citizens, also worked to promote lasting security and stability in Diyala.

• Challenges nevertheless remain.  Greywolf brigade is the first to leave Iraq without a formal relief-in-place by a unit outside the theater, but other U.S. forces within the theater have assumed responsibility for Diyala in order to maintain security.  Coalition forces are not yet in an overwatch role, but rather continue to work with the Iraqi Security Forces and the local population to enable them to take control of their own security.

Do yourself a favor.  Print it out and read it.