You know what, you're absolutely right, and I stand corrected, he was not in the U.S. Senate at the time. My fault.

Now....as far as his public comments and votes he DID cast....

First, he voted along with Hillary Clinton for about $300 billion in war funding after entering the Senate in 2005

Second, from 2003 to 2008, he waffled several times about his support of the Iraq war. At one time he said he would have voted against it. Then he said that it was possible he would have voted for it, based on the classified intelligence reports provided to the U.S. Senate. He also made statements in late 2006-early 2007 in support of the war, and if memory serves me (I'll stand corrected if I'm wrong), a few of those sentiments are found in his book.

Related....after the first election in Iraq after Obama took office, Joe Biden went on Larry King to celebrate the fact that elections were taking place, and the message Biden was giving was one where, if you didn't know any better, you'd swear the entire war and the objectives were their idea.

I think a fair statement is that his support (or opposition ) to the Iraq war is much like his support (or opposition) that he and Michelle Obama have had on the topic of late term and partial-birth abortions...."bet hedging"