With most of America screaming for troop withdrawl, I am not yet convinced that sectors of rebelious Sunnis aren’t intentionally reducing their number of attacks until we do withdraw. Then they will have an almost unresisted freedom to slaughter the Shiites with their homemade cheap, but seriously effective IEDs knowing that our Congress will never permit a return of our troops.
IEDs are not a particularly effective weapon against people who are willing to drive Sunnis wholesale out of particular areas. Once the Sunnis are gone, so are the IEDs. Just ask Sheik Samarrai.
There's nothing particularly magical about IED's - they're glorified land mines. They're the modern equivalent of the ancient technique of digging concealed pits with sharpened stakes at the bottom. The Sunnis can't win the war using IED's against Shiites because the Shiites - in the absence of Uncle Sam's restraining presence - will simply kill everyone and destroy every structure within some distance of the IED. This kind of strategy has worked in every military campaign in which it has been deployed. We are too squeamish to use it because we are Americans. I guarantee you that Iraqi Shiites don't share our moral qualms.