For a while here, it seems that we’re witnessing something rather special: a Hollywood war movie that not only excites and enthrals, but also puts its money where its blood-filled mouth is.

Adapted from Washington Post journalist David Ignatius’s novel by Oscar-winning screenwriter William Monahan (The Departed), it keeps a vice-like grip on reality for almost an hour... before disappointingly caving in to the (American) conventions of the genre.

What we have here, people, is Tom Clancy with a liberal streak.

As terrorists hit Manchester on their latest bombing tour of Europe, we find the CIA’s best field operative Roger Ferris (DiCaprio) doing his darnedest to find the ringleaders in Iraq - growing his beard and threatening unhappy suicide bombers and the like.

Barking orders back home is Ed Hoffman (Crowe), a brash and unyielding strategist with a wife, two kids, a beer-gut and a permanent earpiece.

The trouble is, both Hoffman and Ferris think they’re running the show and it’s getting them nowhere. Matters get even more complicated when the operation moves to Amman, Jordan, where super-suave intelligence chief Hani Salaam (Strong) really does run the show.

The man they are all seeking is Al-Saleem, a dyed-in-the-kaftan zealot who also has rather high opinion of himself. Basically, this whole War on Terror thing is one giant, collective ego trip.

Be that as it may, Ferris can expect full cooperation as long as he sticks to Hani’s only rule: “Never lie to me.” Oh dear. The words are barely out of his mouth before Ferris is off chasing someone he shouldn’t and getting savaged by dogs in a filthy alley.

This does, however, afford a meeting with delicious doctor Aisha (Golshifteh Farahani). And from the moment she appears you know exactly where this is heading.

Knowing what’s at stake and the bigger picture, would a seasoned campaigner like Ferris give himself an Achilles heel by consorting with a vulnerable young local? No, he wouldn’t. Heck, at one point he doesn’t even expect to return to Amman.

Their relationship is one of several plot points that don’t wash. But at least the film puts it to one side while Ferris and Hoffman decide to get Al-Saleem’s goat by creating their own splinter cell, enlisting a reclusive English hacker (Simon McBurney) to set up an unsuspecting architect as its putative leader.

It’s a riveting but under-exploited conceit, the plan going belly-up all too quickly as the film accelerates to a sweaty climax which, for all its tension, suffers a mild dose of the Hollywood cop-outs.

Still, if you ignore A Good Year - which most people did - the Russ 'n' Rid combo generally packs a punch. And so it is here as Crowe puts his considerable weight (plus an extra 50lbs) behind a central performance from DiCaprio who once again commands authority despite his youthful looks.

But the acting honours go to Strong who effortlessly nails the unaffected confidence of a man with absolutely no self-doubt.

With high-class acts to match the hi-tech savvy of Scott and his trusty crew (cinematographer Alexander Witt, editor Pietro Scalia, composer Mark Streitenfeld), this is as taut and engrossing a couple of hours as you’ll experience all year.

Elliott Noble