Barack Obama was on the defensive at the AFL-CIO forum in Chicago last night, taking hits from both Christopher Dodd and Hillary Clinton over his recent comments about Pakistan. But as Ben Smith reports, Obama fired back forcefully with his trump card, opposing the Iraq war. Here's a slimmed down version of the exchange last night, starting with Senator Dodd reiterating his criticism of Obama:

DODD: I think it's highly responsible - or irresponsible for people who are running for the presidency and seek that office to suggest we may be willing unilaterally to invade a nation here who we're trying to get to be more cooperative with us in Afghanistan and elsewhere.

So my views - and I say this respectfully to my friend from Illinois here - I think it was wrong to say what he did in that matter. I think it's important for us to be very careful about the language we use, make it clear that if this United States is going to build the relationships around the world, we're going to have to do so with allies, in some cases allies that we may not particularly like.

OLBERMANN: Senator Dodd, thank you. Senator Obama - yes, you've taken some hits here from us, so yours is the last word on this subject.

OBAMA: Well, look, I find it amusing that those who helped to authorize and engineer the biggest foreign policy disaster in our generation are now criticizing me for making sure that we are on the right battlefield and not the wrong battlefield in the war against terrorism. (Cheers, applause.)

And, Chris, respectfully - and you and I are close friends - but the fact is you obviously didn't read my speech. Because what I said was that we have to refocus, get out of Iraq, make certain that we are helping Pakistan deal with the problem of al Qaeda in the hills between Afghanistan and Pakistan. But, Chris, if we have actionable intelligence on al Qaeda operatives, including bin Laden, and President Musharraf cannot act, then we should. Now, I think that's just common sense.

Senator Clinton immediately piled on, saying that presidential candidates should not "engage in hypotheticals" while adding in the very next breath that a unilateral strike on bin Laden inside Pakistan "may well be the strategy we have to pursue based on actionable intelligence." Clinton finished with this reprimand of Obama which drew a chorus of boos from the crowd:

So you can think big, but remember, you shouldn't always say everything you think if you're running for president, because it has consequences across the world. And we don't need that right now.

Obama is being attacked on all sides for stating the obvious, which is that we would take out bin Laden with a missile strike if we had a high degree of confidence in his location - whether that was in Pakistan, Iran, or wherever - and almost everyone criticizing Obama admits they would do the same thing. So is Obama speaking common sense or showing bad judgment?

It reminds me of a similar - albeit inexact - comparison. In April 2001 President Bush set off a diplomatic firestorm by stating in a television interview that we would do "whatever it takes" to defend Taiwan against Chinese aggression. Of course, this was a message the U.S. had been sending to the Chinese for decades - the Taiwan RelationsAct of 1979 strongly implied (but did not mandate) intervention by the United States, if necessary, "to resist any resort to force or other forms of coercion that would jeopardize the security, or the social or economic system, of the people on Taiwan." Yet Bush took a beating for stating as much publicly and upsetting the United States' well established policy of "strategic ambiguity" with respect to the China-Taiwan issue.

Obama is in a somewhat similar position. Specificity is fine - even desirable - when talking about most policy proposals, including national security. But getting specific about the application of military force is a different matter - even if it does represent what most people consider "common sense." Last week Obama explicity endorsed one course of military action (unilateral strike against bin Laden) while ruling out another (use of nuclear weapons), and by doing so he's given his opponents in the Democratic primary - and certainly his Republican one should he make it through to the general election - an opening.

What's fascinating is that the issue cuts both ways, especially in the Democratic primary, depending on how it's framed. On one hand, it's a negative for Obama in that it highlights his biggest vulnerability: inexperience. On the other hand, if Obama can set successfully leverage his opposition to Iraq into framing it as "fresh thinking" versus the calcified conventional wisdom of Washington insiders like Dodd, Biden, and Clinton, it can be a positive for him with Democratic primary voters - as I think it was last night.