What have we gained from Iraq?

Over on Tigerhawk's comments, after I put much effort into research and analysis, I unleashed my formidable rhetorical arsenal (actually I just punched up a quick 10 minute point by point reply) against some two of my favorite local leftists who had some misguided ideas about the world. Screwie Hoolie surrendered with a stock remark about spit, but Lanky Bastard, in a fairly civil way, admitted to overstating some stuff (which he did, and even bothered to double check) but also included this:

Obviously I think this war is foolish and has damaged US interests, and obviously you don't. And even if I've started off snarky, this part is dead serious: if you want to convince me otherwise, what you should do is explain to me the cost/benefit. What have we gained or won (or are likely to gain or win) that is worth what we've paid and continue to pay? That's the key to changing my mind. Give me the bottom line, answer-to-the-stockholders response. Why is this worth it? And while we're being frank, let me ask: what set of circumstances would cause you to believe that this war isn't in America's best interest? I'm curious. ff to mail me if you'd rather not post in comments.

The fact that a left-winger has actually expressed interest in hearing what will essentially be a rational analysis for invading Iraq (even if I suspect that he asked because he doesn't think I'll be able to do it well... perhaps hence the caveat at the end for email so I can avoid any personal embarrasment) just made me so giddy that I figured that I had to give it a shot. I'm actually going to put a little effort into this, so it won't be posted now. When I finish I'll make a new post here and send him the word to peruse (or ignore) at leisure.