A quick follow-up to Mike's thought on that Post piece: There may be "Many versions of 'Bush Doctrine,'" as the piece's headline notes. But the sub-head, "Palin's Confusion in Interview Understandable, Experts Say," is pretty far off the mark. Palin's confusion would be understandable if she'd offered a response she thought reflected the Bush Doctrine, but which was different from the version Charlie Gibson or many viewers had in mind. But Palin ventured no response at all. She was completely unfamiliar with the term, which is not understandable because, regardless of interpretation, the term has circulated widely.
On the other hand, as Jon Chait suggested, maybe Palin couldn't even take a stab at an answer because she's so attuned to various Bush Doctrine nuances she didn't know where to begin.