I have read extracts and book reviews of Huntington's book. My impression is that Huntington overstates his case, but that does not mean that the book is not worthwhile.
Hmmm. My understanding is that he himself admits that he overstates his case for emphasis, it being rather hard to construct a theory of international relations out of gelatin.
In any case, I'm looking forward to reading it. I may post some of it when I'm finished.