While it was a bit choppy, I'd have to say Obama's speech today was an epochal stride towards dismantling the conservative advantage on foreign policy--attacking its rhetorical substructure in way Democrats have not done before.
To wit, by saying John McCain's Iraq policy "isn't about winning; it's about staying," he called out the talismanic conservative obsession with "victory"--a psychologically satisfying trope wielded, to great effect, against Harry Truman's policy of containment and the "backstabbers" that "lost Vietnam" (cf. Why Not Victory?, Victory is Possible, and Choosing Victory for more historical examples)--and replaced it with a more accurate description of reality.
Second, by calling the conservative approach to Iran "naïve," he turned the rhetorical tables in an important way. Their policy is naïve. It basically posits that with enough "moral clarity" and willpower, which--absent military rollback--manifests itself in the real world as name-calling and posturing, America's enemies will simply capitulate.
That is stupid on its face. But liberals often point this out in a studious, technocratic way that makes them sound like Piggy from Lord of The Flies--allowing Republicans to exploit the nagging, Spenglerian suspicion Democrats will lead America to defeat and civilizational collapse.
By appropriating "naïve," Obama inoculates himself from this charge, makes conservatives look like children, and attacks their stewardship in a way that's satisfying on a gut level--as well as a rational one.
--Barron YoungSmith