On the reduction in violence, Thomas Ricks did this online chat earlier this month:
Montreal: Hi Tom. Thanks so much for doing these chats. Over on Andrew Sullivan's blog he posts a mother quoting her son who's serving in Iraq. He says: "No one ever mentions the fact that we have literally built walls around each neighborhood and along every highway as the reason the violence is down here. The place looks like an Orwell novel gone wrong. The people cannot shoot each other through walls and the insurgents cannot move around to plant their bombs. A society cannot function walled off form each other. We pay every bill, manage every facet of governance. The government at every level is a joke. The ministries are controlled by one faction (Shia). They have almost no experience or education. A bunch of guys walk around in suits and look important while they do nothing." How big a deal is this wall-building? What's the long term plan for the walls?
Thomas E. Ricks: I know the initial Iraqi reaction to the walls was unhappy, in part because it supposedly evoked images of Israel.
That said, the walls do seem to have had an effect in reducing violence, especially against Sunni neighborhoods that were being ethnically cleansed by Shiite militias. (And yes, another reason Baghdad is quieter is that ethnic cleansing has been completed in much of the city.)
(WashingtonPost.com)