Sean Connery, Alec Baldwin and Scott Glenn in the film adaptation of The Hunt for Red October. Photograph: Sportsphoto Ltd/Allstar  Clancy's debut introduces CIA analyst Jack Ryan in a tale of a Soviet nuclear submarine commander, Marko Ramius, (played by Alec Baldwin and Sean Connery respectively in the movie) who wants to defect to the US with his sub, while convincing his bosses that it has been sunk. The novel sets the template for Clancy's blend of espionage and military thriller, inaugurating a series that will influence film and TV as well as other authors – not by chance is the hero of 24 called Jack Bauer, and Homeland's apocalyptic second-season finale was highly Clancy-esque.  Ryan advances to near the top of the CIA in a novel about the Reagan-era "war on drugs", reflecting Clancy's closeness to the Republican president. Different US agencies conduct a covert campaign against a Colombian cartel (the titular clear and present danger). However, the hero is unusually cast as a quasi-dissident within the agency, left out of the loop initially and pressing colleagues and the president to go public about the operation. In intercepting narco-barons' mobile phone calls and keeping politicians in the dark, it has been noted, the semi-fictional CIA of this novel anticipates the post‑9/11 tactics of the NSA and JSOC, as exposed in Edward Snowden's leaks to the Guardian.  The novel in which Clancy "foresaw" 9/11, via a suicide mission in which a plane crashes into the US Capitol, wiping out most politicians and officials including the president – with the result that Ryan, who has already risen during it from national security advisor to vice president, reaches the White House. But talk of the author's prophetic powers is somewhat undermined by this incident occurring during a war with Japan, where an ultra-nationalist faction has seized power. However, other works did eerily anticipate the 2008 Soviet-Georgia conflict (his video game Ghost Recon) and the hunting down of Bin Laden (Dead or Alive).  Ryan, and somehow not Bill Clinton, remains president in Clancy's alternative reality, but the focus is on the eponymous multinational, globe-trotting warrior unit, already fighting the "war on terror" before it officially started three years later. Had any of the organisers of the 2012 Olympics read it (and surely they had?), the last-minute scare about a lack of security staff would have been particularly sleep-disturbing, as it's about a terrorist threat to the 2000 Sydney games. Also notable for exemplifying Clancy's diversification into multimedia – 25m copies were sold of the simultaneously released video game.  Clancy's earliest novels appeared while the Soviet Union still existed, and in his post-1990 work he can be seen as looking for a replacement enemy – ranging from terrorism or drugs cartels to nascent superpowers – menacing enough to justify the paranoid style of his fiction (in the posthumous Command Authority, due in December, Russia is helpfully playing its old role again under "a new strongman" with a dodgy past, returning his oeuvre full circle to its Cold war origins). In this case he's well ahead of the game in identifying China as the next opponent, in a story about a war between it and Russia, with the US allied to the latter.
Tom Clancy, author of 17 New York Times bestsellers, died this week at the age of 66. Here are five key novels of his career. By John Dugdale