Thinking back to Brass Eye’s 2001 “paedophile special”, and in particular the furore it caused among certain sections of the media, it’s easy to see how misunderstood Chris Morris often is. Typically outraged, the Daily Mail described the episode as “a spoof documentary on paedophilia.” Which is missing the point. The programme was a savage attack on the media’s own thoughtless, knee-jerk reaction to a serious issue. It clearly didn’t stop, though, large sections of the press demonstrating their own thoughtless, knee-jerk reaction to the show.

It seems likely, I’m afraid, that those same sections of the media will be up in arms about Four Lions, Morris’ directorial debut, a “jihadist comedy”, no less, focussing on four wannabe suicide bombers in Sheffield. Which is a pity, as Four Lions is an extremely good film; far more than **just** a comedy about suicide bombers.

It’s often tempting to try and guess exactly what Morris’s intentions are from project to project. Radio 4’s On The Hour – and it’s BBC TV extension, The Day Today – were as much about exploring the dynamics and specific technical details of news programmes as they were about sending-up of its po-faced self-importance. Jam – a personal favourite, and another radio-to-TV transfer – resided in an altogether more experimental place, a woozy 4am place of distorted dream logic. Nathan Barley – co-written with The Guardian’s Charlie Brooker – might well have sneered disdainfully at a certain London media archetype, but the show’s great trick was that, in the end, you sort of felt sorry for Barley, however repellent and idiotic a self-facilitating media node he may have been.

So what exactly is Morris – and co-writers, Peep Show and The Thick Of It’s Jesse Armstrong and Sam Bain – doing with Four Lions? On face value, it is, indeed, a very black comedy about four radical Muslims – three young Asians, and one white middle aged convert – who plan to blow themselves, and others, up during the London Marathon. Taken as farce, the film works extremely well. Their leader, Omar (Riza Ahmed), intriguingly, the most conventionally “westernised” character here, is a family man who tells his son bedtime stories, where the animals in The Lion King have become suicide bombers. There’s Fessal (Adeel Akhtar), who is training crows to carry bombs, Waj (Kayvan Novac), who can barely tie his own shoe-laces, and Barry (Nigel Lindsay), a maniacal convert who thinks it’d be quite a good way to punish non-Muslims by blowing up a mosque. The film follows them from their safe house in Sheffield, to the mountains of Pakistan, where two of them intend to train with the Mujahideen, back to Sheffield and on to London, and their intended entry into Paradise. Of course, things don’t go according to plan. The four men are, on almost every level, utterly incompetent. But, equally, they’re extremely dangerous. After all, they have a garage packed with bleach and fertilizer.

Morris has said that “terrorist cells have the same group dynamics as stag parties and five-a-side-football teams. There is conflict, friendship, misunderstanding and rivalry. Terrorism is about ideology, but it’s also about berks.” He cites examples like 9/11 hijacker Mohamed Atta, who when teased for urinating too loudly, apparently blamed Jews for making thin bathroom doors, and Khalid Sheikh Mohamed, who supposedly spent hours looking for a costume that wouldn’t make him look fat on camera.

But in Morris’ universe, everyone in the film is stupid, not just terrorists. There’s Nighty Night’s Julia Davis as a whacked-out neighbour who buys the quartet’s story that they’re in fact a band meeting for rehearsals; or Morris’ regular Kevin Eldon and Smack The Pony’s Darren Boyd as a pair of police snipers who mistake a Wookie costume for a bear costume, with calamitous results, and Benedict Cumerbatch as an inept hostage negotiator. There is plenty of excellent comedy here, much of it quite uncomfortable.

So what’s Morris’ point? Is he simply making topical farce – a black comedy that, in its way, while touching on contemporary issues harks back to the darker output of the Ealing studios? Or, are we to believe that Morris’ aim is to illuminate terrorists as fallible, bickering, ultimately human people? Certainly, it’s true that one of Morris’ ongoing concerns in his work is to rigorously mine his subject, however shocking or taboo it might be, in a manner that demystifies it. Critical to this, I think, is Omar. It’s certainly unsettling to see him sitting in his pleasant, airy suburban house with his attractive wife Sophia (EastEnders’ Preeya Kalidas), discussing blowing himself up in reasonable, assured tones while bouncing his son on his knee. After all, aren’t we conditioned to imagine our terrorists as bearded devils, holed up in remote caves, issuing chilling threats on crudely-shot video tapes? Which, surely, is Morris’ point.

Four Lions opens in the UK on May 7