Last Night's Television - Occupation, BBC1; Flight of the Conchords, BBC4

About three months ago I complained in print about the absence of Iraq war drama on television, disobligingly comparing the virtues of a stage play about British squaddies in the aftermath of the invasion with the absence of anything similar on the small screen. If I'd known that Peter Bowker's Occupation was in preparation I think I'd have been a little more circumspect, because, to a slightly startling degree, it covers very much the same ground as the play I admired so much. It has traumatic military action, it has troubled soldiers returning to Iraq as "security consultants", it has the damage done to civilian relationships and a soldier's sense of purpose. What's more the BBC isn't tucking it away as a fig leaf for the remit; it is stripping it over three successive prime-time slots in the middle of the week, so that the story has a chance to really get a grip on you. It's the sort of serious, ambitious commissioning that justifies the licence fee. In fact, it's almost enough to make you forgive them for Bonekickers.

It's also pretty good, which is always a relief on these occasions. It's easy enough to make high-minded calls for serious drama about the urgent issues of the day, after all, but it can sometimes be hard to watch the result. Not in this case. Peter Bowker begins in the middle of the action, with four soldiers white with tension inside an APC, trying to identify the incoming fire from the noise it makes as it rattles off the armour. And then they're out and in the thick of it... occupying the insufficient gap between a young Iraqi girl and two insurgent gunmen. When a grenade goes off Sergeant Swift's final briefing – "No heroics, we don't lose anybody" – is shredded. One of their group loses a leg and Swift himself does the heroics, carrying the wounded girl through the streets to the nearest hospital.

All these men bring Iraq back home with them, but Swift, played by Jimmy Nesbitt, does it a little more literally than most, setting up a charitable link between a British children's hospital and one in Basra so that the small girl will get treatment. Accompanying her is a female Iraqi doctor who suddenly has a lot more in common with Swift than his wife. Meanwhile, his army friend Danny (Stephen Graham, doughily cheeky as one of life's chancers) is trying to decide between jumping off a balcony and signing up with Lester, an ex-Marine who wants to divert a chunk of Iraq's reconstruction budget into his fledgling security business. And Hibbsy is finding that working as a bouncer doesn't match the camaraderie or the excitement of life "in the green".

Peter Bowker's script is able to stretch from the borderline portentous (some lines of Gilgamesh, to the effect that only emotional treasures have any true value) to the hairline cracks of a marriage ("Doctor something or other or something..." says Swift when he's asked the name of the woman he can't stop thinking about) to barrack-room banter, and it does it without strain. "If he was selling the steam off his shit you'd be buying," accused Swift, angry at Danny's susceptibility to Lester's sales pitch. "There'd be a lot of steam off his shit... have you seen the size of him?" added Hibbs musingly, trying to defuse their row. And although the aftermath of action is the real core of Bowker's concerns – the void that's left when adrenalin has gone – he doesn't starve the viewer of action either. Last night's episode ended with Danny's first private job going seriously wrong after an ambush. Fleeing towards Coalition troops he realises a little too late that he's disguised as an Iraqi himself and that the gun in his hand may well be misinterpreted. So he frantically starts to strip off, every layer revealing something even more suspicious until he's stark naked and plaintively shrieking, "I'm from Kirby!" at the oncoming vehicles. How could you not want to come back for more?

Since I began by eating my words – or at least nibbling one or two – let me swallow a few more. When I wrote about episode one of this series of Flight of the Conchords I suggested that you might feel a short-changed by the songs. In fact, as the series has continued they've had some terrific numbers, balancing on that narrow ledge where a comic number turns into something you'd be prepared to listen to more than once. I'm not sure that "Think about the Epileptic Dogs", a fund-raising number designed to win the heart of a girl they're both attracted to, quite reached that level, but I'm glad I didn't miss it the first time through. "Send us some money/ To stop these dogs from actin' funny/ Send a cheque in a letter to make a setter feel better", they sing, before unwisely moving to a re-mix version, complete with flashing disco lights that causes havoc in their largely canine audience.