As head of security at a diamond mine in South Africa Harry Webb (Telly Savalas) deals ruthlessly with thieves foolish enough to try swiping any precious stones. His methods rankle fellow security specialist Mike Bradley (Peter Fonda) who is secretly enjoying sexy fun times with the daughter of the head of the mining company: fashion model Claire Chambers (Maud Adams). Mike is taken aback when Nelson (Victor Melleney), the mine administrator, gives him an unusual assignment: steal a diamond. It happens security has discovered a team of hard-bitten mercenaries are plotting to raid the diamond mine with the aid of an inside man. So Mike agrees to pose as the turncoat in order to lure the mercenaries into a trap.
Jules Dassin established the style of international caper movies with his classic Rififi (1955). Most of the films that followed in the Sixties took their cue from Dassin's frothier, more glamorous Topkapi (1964) before the genre took a grittier turn in the Seventies. Killer Force, filmed as The Diamond Mercenaries before US distributors American International Pictures re-titled the film for the grindhouse circuit, falls between both stools in that it is grim, gritty and violent yet somehow even more disposable than a kitschy Sixties caper film.
Versatile and oft-underrated British craftsman Val Guest seemingly set out to mount a variation on his classic crime thriller Hell is a City (1960) on a more grandiose and glamorous scale. He assembles an impressive ensemble of Big Name Stars headed by Telly Savalas, then riding high as TV's beloved lollipop-loving detective Kojak. The onetime Blofeld is one of three veterans of the James Bond franchise that appear in this film. Including two-time Bond girl Maud Adams who amps up the glamour in a smilier role than usual despite her role in the unfolding heist proving somewhat unclear. In fact the same holds true for Telly. As suavely menacing Harry Webb, he waltzes away with the movie snagging what few memorable moments there are. Notably a steamy albeit unnerving scene where he accosts Claire by way of interrogation. Yet his character has little bearing on the actual plot. He is a novelty guest star there to lure unsuspecting Kojak fans into theatres. Even Telly's wardrobe lands its own special screen credit (Vincci of London, in case you are interested).
By comparison a frizzy-haired, scraggly bearded Peter Fonda proves an underwhelming hero, phoning it in even when canoodling with a naked Maud Adams. A decent enough actor in the right role, Fonda was still never the leading man his father was. Here Mike's blank reaction to a shock death in an early scene sets the tone for a character who ought to be charismatic and mysterious yet instead proves weirdly diffident and uninteresting with a snarky one-liner for every occasion. Unlike say Blood Diamond (2006), Killer Force does not get into the dubious politics underlining the international diamond trade. It is merely there to provide a sexy backdrop for a band of colourful antiheroes. Mildly more intriguing than the chief protagonist, the mercenaries include pipe-puffing mastermind Hugh O'Brian, maniacal knife wielding (also poetry loving!) aristocrat Christopher Lee (who does not get a reunion with Maud Adams, his co-star in The Man with the Golden Gun (1975)), gor blimey cockney geezer Ian Yule, barely characterized Michael Mayer and - uh-oh! - jive-talking O.J. Simpson. Back when the Juice was a regular featured player in starry ensembles from The Towering Inferno (1974) to The Cassandra Crossing (1976) rather than a celebrity murder suspect.
Further hindered by that strange lack of urgency adventure films had back in the Seventies, Killer Force can't quite make up its mind whether the mercenaries are tragic antiheroes or out-and-out psychopaths. It is also strangely lackadaisical about its big plot twist which is not all that surprising anyway. The diamond heist itself involves a lot of slow, methodical skulking around the desert with occasional goofy moments. Things pick up near the finale when Guest belatedly lets loose with the gunfire and blood squibs and stages impressive car chases across sweeping desert vistas shot from a helicopter's P.O.V. Even then the inconclusive shrug of an ending proves less than satisfying.