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 "na