Tom Clancy's Jack Ryan is ending with season 4, meaning it's the last chance for another major figure from the books to appear. While Jack Ryan has changed actors nearly as often as James Bond, the key difference is that Jack used to swap faces in almost every outing. On the big screen, only Harrison Ford has played the CIA analyst more than once, but with Amazon's Jack Ryan, John Krasinski has been given multiple seasons to make his mark on Clancy's most famous hero. While Jack Ryan will end with its upcoming fourth series, a spinoff fronted by Michael Peña is currently in the works.

https://screenrant.com/jack-ryan-season-4-john-clark-appearance/