One of the major dilemmas for any fan of Hollywood blockbusters over the last decade has been how to explain what has happened to Harrison Ford. This is the man who played the two coolest cinematic characters to have merged in the final quarter of the 20th Century.

This is Han Solo. This is Indiana Jones. This is also Deckard from Blade Runner, another all-time iconic film character, and a man Oscar-nominated for his starring turn in the serious and restrained Witness. He was not just a sci-fi and action film star – he was a man who could genuinely act. Not only that, he still had it right up until the mid 1990s, with turns as Jack Ryan in Patriot Games and Clear and Present Danger and Richard Kimble in The Fugitive.

Where did it all go wrong for Harrison Ford? Well, shall we say he hasn’t managed to make a single decent film since 1994? Quite what triggered his decline in both acting ability and his ability to choose interesting projects is very hard to say, but in the last decade the closest he’s come to being the true movie star we all used to know, love and want to be was the mindless 1997 actioner Air Force One.

Han Solo cannot be written off, and nor should Indiana Jones – so a new Harrison Ford action movie is bound to attract a lot of attention even after the disappointments of the last 10 years. Sadly, however, pretty much every time a new Harrison Ford action flick comes up, it’s almost exactly the same premise as The Fugitive – one man having to battle against overwhelming odds despite not having any knowledge or training in fighting criminals. This time there’s also an element of Patriot Games as Ford’s computer security expert finds his family threatened by terrorists – just as Ford’s CIA man found his family threatened by terrorists in that earlier, rather superior movie.

So, an aging computer expert unbelievably turns action hero to take back his family, kidnapped by bank robbers who want him to steal a load of money for them. Let’s face it, it’s rather hard to envisage Indiana Jones as a computer geek. An archaeology geek, perhaps, but Indiana Jones would never be stuck behind a keyboard. The fact that you get very few computer experts in their late 50s/early 60s just makes it more confusing – why have Harrison Ford in the lead when the part is so obviously better suited to someone half his age? The fact that the dumbed-down technical talk is inane to anyone with even a passing knowledge of computers and that Ford still manages to say his geeky lines as if he’s trying to read Sanskrit simply makes the whole set-up that less convincing.

But still, this is an action thriller – plausibility goes out the window as soon as you start to dissect anything from that genre. You’d think they would at least have tried, though. As it is, the one saving grace is Paul Bettany as the chief baddy – a good actor showing a restrained villainy that’s very rare in this kind of film, where even the best actors tend to go over the top. It’s just a shame that Ford couldn’t have summoned up a similar kind of restraint and turned down what is, compared to his early, iconic film work, yet another disappointment. If this is the best he’s got, it really doesn’t bode well for the rumoured revival of the Indiana Jones franchise.