The film adaptation of Tom Clancy's 1993 novel 'Without Remorse' had been in development since the 1990s. In 1994, Keanu Reeves was offered $7 million for the role of John Clark but turned it down. In 1995, the film, which was set to be written and directed by John Milius and would star Laurence Fishburne and Gary Sinise, was two weeks away from shooting, before it was shut down, due to the financial collapse of Savoy Pictures. In 2012, Christopher McQuarrie signed on with Paramount Pictures to direct the film, with Tom Hardy in talks to play John Clark and Kevin Costner in talks to play his mentor, William Harper. In September 2018, it was announced that Michael B. Jordan would be playing John Clark in a two-part film series, which will be composed of 'Without Remorse' and 'Rainbow Six'. Director Stefano Sollima was announced in December 2018 and filming began in Berlin in October 2019.
John Kelly/Clark has been played in other Tom Clancy movies by Willem Dafoe in Clear and Present Danger (1994) and Liev Schreiber in The Sum of All Fears (2002). This is the story of how he came to be associated with the CIA.
Other than a few characters names, this movie has nothing else from the novel. It's a completely different story and plot.
The character of Karen Greer is revealed to be the niece of James Greer from the Jack Ryan stories, who is Jack Ryan's close friend and mentor.