After all these years (and several re-readings of The Hunt for Red October), finding a pure Tom Clancy novel that I’ve missed helped fill several hours of travel. Without Remorse delves into the background of John Clark, a constant Jack Ryan companion in many of the novels. Clark was memorably played by Willem Dafoe in the 1994 film Clear and Present Danger. (Dafoe is too small, but otherwise matched the character of this novel.)
Without Remorse takes place in the 1960s and early 1970s, prior to the Ryan universe. Here’s a plot summary, courtesy of Wikipedia. I’m just glad this was written by Tom Clancy, instead of being part of “Tom Clancy’s” world, penned by any number of other folks.