Of course, the Kremlin has no cardinals, that's the Vatican. But it's a pretty good title for a pretty good book by Clancy.
I was reminded of Le Carre a bit, although Le Carre loves the moral ambiguity of the spy world where Clancy doesn't really touch on it. But the book, despite its age, holds up pretty well. It was never made into a movie, so perhaps that's why it doesn't have the name recognition of Clear and Present Danger or Red October. (It's also not as good as October, I'd say, though I liked it better than Patriot Games and I haven't gotten to C&PD yet.)
There is one scene in the middle of the book that doesn't play well–a ploy Ryan uses where he goes after the manhood of a gay senator in order to make the Russians think … well, that part's not really important. Anyway, it's really out of place and since at the beginning it wasn't 100% clear it was a ploy, it was really really out of place.