The Cardinal of the Kremlin is a novel by Tom Clancy, featuring his character Jack Ryan. It is a sequel of sorts to The Hunt for Red October, based around the development of the Strategic Defense Initiative and its Soviet equivalent, covering themes including intelligence gathering and counterintelligence, political intrigue, and guerilla warfare in Afghanistan.
This book is notable for its outrageous (yet plausible) conclusion and the increasing predominance of pro-military, pro-law enforcement views endorsed in Clancy's writing. It is also the closest to a straightforward spy novel of all of his books.