Dir: Phil Alden Robinson. US. 2002. 124 mins.

It's not the efficiently staged action that stands out in the fourth movie adapted from Tom Clancy's series of best-selling Jack Ryan political thriller novels. Nor even the debut of Ben Affleck as a younger, sexier incarnation of CIA stalwart Ryan. Rather, it's the now doubly chilling moment in the film - shot months before the events of September 11 - when a nuclear bomb planted by foreign terrorists goes off at the Super Bowl, destroying Baltimore and throwing the world into a doomsday panic.

How that moment - and the more fanciful scenario that surrounds it - will play with audiences around the globe is difficult to gauge. While major releases like Collateral Damage and Big Trouble have dealt obliquely with bombs and terrorism since Sept 11 (and have failed commercially), The Sum of All Fears offers an explicit take that US moviegoers especially may find hard to handle. On the other hand, the film's sober, patriotic treatment of its subject matter could strike a chord and pique fresh interest in a franchise that has been dormant since 1994's Clear And Present Danger, the most successful of the Ryan movies so far with a worldwide gross of over $212m. Having carefully avoided the appearance of exploitation in its marketing campaign, Paramount launched the latest Mace Neufeld-produced instalment of the Ryan franchise in the US to surprisingly impressive returns - $31.2m to take top spot over its opening weekend.

The film's script, by Paul Attanasio (Quiz Show, Donny Brasco) and Daniel Pyne (The Firm, Any Given Sunday), makes some significant changes to the plot of Clancy's 1991 novel. The deputy director of the CIA in the book, on the screen Ryan is a promising young analyst at the Agency. Pulled from the ranks by CIA Director Cabot (Freeman) to advise the US President (Cromwell) on his new Russian counterpart, Ryan finds himself struggling to avert an all-out US-Russian nuclear war. The war has been fomented by European neo-Nazis (the book's villains include Arab as well as European terrorists) who hope to seize power by pushing the US and Russia into a devastating war.

Affleck, for whom the part was re-written after Clear And Present Danger and Patriot Games star Harrison Ford passed on a third movie, makes an appealingly youthful, but still believable Ryan. His presence, and the romance that the re-written part allows, should help broaden the appeal of the film beyond the franchise's core older audience. Freeman fills his now almost customary role as the tough mentor to an ambitious, talented protege. The two leads are supported by a cast of character actors - including Alan Bates as the louche neo-Nazi mastermind - who should add to the film's mature appeal.

As topical as some of the events seem, the film's plotting and characterisations (based, after all, on decade-old source material) sometimes have a familiar, slightly weary feel. After a talky first half, however, the film is galvanised by the shocking success of the Super Bowl attack. Taking over the franchise from Clear And Present Danger and Patriot Games director Phillip Noyce, director Phil Alden Robinson (Field Of Dreams, Band Of Brothers) brings his recent TV documentary experience to bear, shooting scenes in the aftermath of the blast with a washed-out and hand-held cinema style that provide additional immediacy (though most of the violence is implied rather than seen, the film's PG-13 US rating comes with an advisory note about "disaster images"). The nuclear brinkmanship action that dominates the film's latter stages was captured with support from the US military and makes for an effectively exciting climax.

Prod co: Paramount Pictures
US dist: Paramount
Int'l dist: UIP
Prod: Mace Neufeld
Exec prods: Tom Clancy, Stratton Leopold
Scr: Paul Attanasio, Daniel Pyne, based on the novel by Tom Clancy
Cinematography: John Lindley
Prod des: Jeannine Oppewall
Ed: Neil Travis
Music: Jerry Goldsmith
Main cast: Ben Affleck, Morgan Freeman, James Cromwell, Liev Schrieber, Alan Bates