I did read the book and watch the movie back in the 90s sometimes. My memory about them isn't all that great. What I remember about both is they were pretty boring. Boom, mic drop.
The thing about the book is that it's actually a prequel to A Hunt for Red October. It's supposed to be about Jack Ryan before he really started working for the CIA and junk. Somehow he gets involved with a plot involving the IRA. And mayhem ensues, though it's not that interesting.
The dumb thing about the movie is they cast Harrison Ford as Jack Ryan in this one after Alec Baldwin played the same character in A Hunt for Red October. So even though it's supposed to be a prequel, they cast someone older to play the character! Although this wasn't the first time Harrison Ford replaced Alec Baldwin; in Working Girl, Baldwin was Melanie Griffith's cheating boyfriend and then she ends up with Ford. And then after another of these Jack Ryan movies they replaced Ford with Ben Affleck and then Affleck was replaced by Chris Pine years later. Anyway, I think I watched a lot of this movie in fast forward because it wasn't all that interesting.
So really I wouldn't recommend the book or movie unless you want to be bored.