2. Has the “surge” in troop levels played an important role here as well?
Not really. Where once there was one country called Iraq, there are now three emerging states: one Kurdish, one Sunni, and one Shiite. More than two years of sectarian violence have left districts in and around Baghdad completely Sunni or completely Shiite, and that has significantly reduced violence in those districts and resulted in fewer bodies in the streets. This new strategic reality, combined with huge cash payments to the Sunni insurgent enemy, is what has given U.S. forces a respite from the chaos of the last four years. The introduction of a few thousand additional troops into Baghdad’s neighborhoods was never going to result in any kind of strategic sea change.

Harpers Magazine online posed 6 questions on Iraq and the ongoing Surge to retired army colonel and author Doug Mcgregor. His answers are not of the "matrix" and as usual challenge conventional wisdom. Considering the MG Scales oped on culmination, Macgregor's answers offer up a different conceptualization of the war in Iraq and the way ahead.

http://harpers.org/archive/2007/11/hbc-90001783