Ross Douthat and Kristen Soltis are less than happy with Palin's interview performance. I have mixed feelings. Yes, I would've been happier if she'd shown some sign of having heard of "the Bush doctrine" as a term that's been thrown around in foreign-policy circles. On the other hand, I read a decent amount about foreign policy and had not seen much mention of "the Bush doctrine" for several years, and as noted elsewhere its meaning has been vague and varied.
I think the honest approach, as David Frum suggests, is that she emphasize that her expertise is in domestic policy, especially involving energy and reform, and that she's learning about foreign policy, knows how to get needed information and assemble a reliable team, and could rise to the task if she were to become president in the next four years. I also think that anyone who's criticizing her lack of foreign-policy expertise but also voted for Bill Clinton in 1992 is incoherent.