On Tuesday, it's out on DVD ($29.99 list), but on VHS it will only be available to rent.
Although Clancy is widely derided by book critics, he now has one of the most consistent movie track records of any novelist. In contrast, 48 adaptations have been made of the venerated novels of Henry James, with not many more successes than Clancy has enjoyed in only four tries.
Despite his literary awkwardness, Clancy is, pre-eminently, a man who knows how things work. Perhaps that's the authorial quality that movies can use best. James M. Cain, author of the novels behind such screen classics as "Double Indemnity," "Mildred Pierce," and "The Postman Always Rings Twice," also knew the value of research.
Clancy's movie success is particularly striking because his doorstop books ("Sum" weighed in at 928 pages) seem more suited to 8-hour miniseries than to 2-hour films.
Worse, "Sum" is the fifth in the 10 volumes tracing the world-shaking rise of Ryan, Clancy's alter ego, from a CIA analyst's cubicle to the Oval Office. Clancy's pseudo-history is even more detailed and obsessive than George Lucas'.
Fortunately, Mace Neufeld, the Hollywood veteran who has produced all four Jack Ryan movies, chose to mostly ignore Clancy's vast superstructure. With Clancy's approval, he hired 29-year-old Affleck ("Changing Lanes") to play Ryan, though Affleck is 23 years younger than Harrison Ford was when he starred in the last Ryan movie, 1994's "Clear and Present Danger." Affleck's age makes it impossible for the series to faithfully follow Clancy's increasingly unwieldy alternative universe.
In this movie, Ryan has regressed to a junior Kremlinologist and bachelor, who has just met the lovely doctor who was his wife in the last three films. Confused? Don't worry. This installment is designed to stand on its own.
Affleck, who started out in Damon's shadow, seems to growing suspiciously more youthfully beautiful with each passing year. If he wants grown men to identify with him in future Jack Ryan movies, he should let the maturation process take its natural course.
Fortunately, he shares the screen with many fine veteran actors, most notably Morgan Freeman ("Shawshank Redemption") as Ryan's brusque mentor, CIA boss Bill Cabot. Despite the somberness of the plot, Freeman is hilarious in his role.
Screenwriters Paul Attanasio ("Quiz Show" and "Donnie Brasco") and Daniel Pyne (James Woods' witty "The Hard Way") borrowed the novel's basic premise and characters, and then constructed a story that's reasonably true to Clancy's spirit, yet is surprisingly easy to follow. Director Phil Alden Robinson ("Field of Dreams") comes up with some memorable images and sets an ideal pace.
The storyline, though, has been overtaken by events. Clancy published "Sum" in 1991, before the collapse of the Soviet Union, when the risk of a misunderstanding between Moscow and Washington escalating to a nuclear exchange was far greater. The screenwriters probably should have updated it to a U.S.-China confrontation over Taiwan.
Still, the outdatedness of the plot is a useful reminder in these days, when we are constantly told that we are in a war without end against Islamist extremism, that, as Lord Palmerston noted, nations do not have permanent enemies, only permanent interests.
Less forgivably, the filmmakers discarded the most up-to-date aspect of Clancy's story due to political correctness. In the novel, the terrorists sparking the nuclear confrontation are mostly Middle Eastern. Fearing charges of prejudice from the Council on American-Islamic Relations, they lost the Muslim terrorists. Instead, they hired stage legend Alan Bates to play an evil billionaire neo-Nazi mastermind intent on leading the Fourth Reich to world conquest -- a role so silly it's probably an intentional self-parody of Hollywood's Germanophobia.
Military technology aficionados will denounce some of the inaccurate details. For example, the nuclear-armed B2 Stealth Bombers ordered to bomb Russia sortie from the U.S. Air Force base at Aviano, Italy, even though all B2s are actually kept at Whiteman AFB in Missouri. This is an intentional error, though, one that shortens the time until the apocalyptic threshold is crossed. It adds to the wrenching Air Force One scenes of good men making bad decisions under unbearable pressure.
Still, in one key detail, "Sum" is the most technically realistic film I've ever seen: all the PCs use Microsoft Windows rather than one of those goofy only-in-the-movies custom operating systems that displays characters two inches tall.
Rated PG-13 for violence, disaster images, and brief strong language.