If you want to understand why the mainline Democrats won't talk about Iraq you should read Robert Kaplan's piece in the June issue of The Atlantic called "How We Would Fight China; The Next Cold War." The gist of the article is given thusly: "The Middle East is just a blip...China constitutes the principal conventional threat to America's liberal imperium" in the 21st century.
"Liberal Imperium" being a good thing, you understand. That's the key to the silence of the Democrats on Iraq.
Kaplan then gives a Kissinger/Brzhinsky style overview of the foreign policy that any future administration will be required by the laws of geopolitics to pursue as China becomes a competing superpower. Any administration. Clinton, Edwards, Kerry, Obama. At this metastrategic level, it won't matter. That's Kaplan's point.
Steely eyed realism for grown-ups is the basic posture in the specialized venues where US foreign policy really gets determined. If you haven't been exposed to this posture, you should rectify that situation immediately. Richard Holbrooke doesn't agree with Condi Rice on a lot of things, but, if Kaplan is right, he understands that US bases in Iraq and the various 'Stans will come in handy 30 years down the road. That's just how these people think, and when the mainstream Democratic presidential contenders sit down with their foreign policy teams behind closed doors, that's how they think too...