And yes, he may have cosponsored Joe 'Republican' Lieberman's S.J.RES.46, the Iraq War Resolution, and also later voted for it in the full Senate to authorize the use of military force against Iraq, but having just read this foreign policy speech, I think he's learnt his lesson from that particular mistake - he publicly apologised later.
Here a brief extract from the speech, I think you'll find it both enlightening and very refreshing.
"The war on terror is a slogan designed only for politics, not a strategy to make America safe. It's a bumper sticker, not a plan. It has damaged our alliances and weakened our standing in the world. As a political "frame," it's been used to justify everything from the Iraq War to Guantanamo to illegal spying on the American people. It's even been used by this White House as a partisan weapon to bludgeon their political opponents. Whether by manipulating threat levels leading up to elections, or by deeming opponents "weak on terror," they have shown no hesitation whatsoever about using fear to divide.
But the worst thing about this slogan is that it hasn't worked. The so-called "war" has created even more terrorism—as we have seen so tragically in Iraq. The State Department itself recently released a study showing that worldwide terrorism has increased 25% in 2006, including a 40% surge in civilian fatalities.
By framing this as a "war," we have walked right into the trap that terrorists have set—that we are engaged in some kind of clash of civilizations and a war against Islam.
The "war" metaphor has also failed because it exaggerates the role of only one instrument of American power—the military. This has occurred in part because the military is so effective at what it does. Yet if you think all you have is a hammer, then every problem looks like a nail."