This business of Obama being superior because he "got it right" on Iraq is pure hog-wash. He was a state legislator at the time from a liberal section of Chicago. He was just beginning to assemble a primary campaign to run for the Senate. There is no comparison between the ease with which he could speak of it being a "dumb war" to the Senators in office facing a president with 85% approval and a country where almost an equal number wanted us to confront Iraq. I'll give Obama props for speaking forthrightly and correctly about the war at the time, but in no way does it tell us what he might do under far different circumstances as President of the United States.
Being able to do the right thing on foreign policy as president has a lot to do with the political support you have back at home. On the question of which candidate can win the support in the Congress and the support of the American people to pursue their policies I think it's almost impossible to say Obama would come in and do a better job than Hillary. In fact, to his opponents he'll present an easy mark - a young, inexperienced one term senator with a narrow base of political support among the liberal elite of the northeast and west without the combined skills and 35 year experience of the Clintons. As Hillary says, we can't afford that.