Red Storm Rising broke new ground as it was the first time in literature that World War III was depicted without the use of nuclear weapons (though it comes close). This was the first Clancy book I ever read and I thought it brilliant. The characters are great, the battle scenes are vivid and tense, the intrigue well thought out.
The NATO-Warsaw Pact scenario has obviously dated, but there are moments in the book that betray its age - the F-19, speculation about the Victor-III subs pod, and the way the MiG-29s are described (the description is of the old artist conceptions before the plane was publicly unveiled). Being a Brit, I found the portrayal of the British characters were close to being comical and stereotypical. The same goes for the Norwegian sub captain, and French and German characters. The climax is pretty good, but it came across a little rushed.
Rather brilliantly though, the book, despite its mammoth length, rarely falters in pace. Just when it seems to be slowing down, we'll jump to another scene and it'll pick up again.
Personally I prefer this book to most of the Jack Ryan novels. I noticed some reviewers accused this of being jingoistic. There's no real flagwaving going on here, unlike the Ryan books. And the Americans aren't always perfect. One Admiral's arrogance results in the sinking of several ships including a French aircraft carrier, and the USS Saipan with 2000 Marines onboard. Later, "Beagle's" reported sightings of Soviet fighters on Iceland are registered as "unconfirmed" resulting in a disastrous bombing raid which sees several B-52s getting shot down by MiG-29s.