This is book 1 of the "Jack Ryan" series.

This note does not contain major spoilers for the book.

Clancy's first published novel, and still the best. It was originally published by the Naval Institute Press; took two years after that for a mainstream publisher to bring it out. Then it took off like a rocket.

Despite remembering it fondly, I haven't gone back to it much. If I've reread it at all in 20+ years, I don't remember it. I certainly haven't reread it frequently, or recently.

I did enjoy reading it again this time. I didn't find anything new I noticed in it, but it was fun to replay the story. And fun to see Jack Ryan before he was promoted to demi-god status :-).