I'd heard this story before, but only as hearsay; not with a link to the Clinton letter, and more specifically, I hadn't heard that the think-tank people now comprised a good segment of the Bush administration.

'Wolfowitz doctrine' is fairly well known, as my diplomat brother tells me. I read about it first time few months ago in Harper's, and have seen references to it several times since.

You might find these several posts lifted from an university mailing list for diplomats and historians interesting.