It takes a special sort of show to make a comedy out of a bomb disposal unit in contemporary Afghanistan; a show that dives into the dark, dank hollows of a man's heart, then drags its way painfully out, up the ridges of thwarted hope and bitter laughter. Or else, you could do it Dad's Army-style, using the war mainly for uniforms and comedic scenarios, making sure the only people who die are idiots or invisible insurgents in far-off sheds. That's what BBC3's Bluestone 42 (pronounced four-two, if you want to pretend you watched it, and not watch it) has done: it's very broad and kind, and I was impressed by it. It was confident and deft, and brooked no squeamishness, no uncertainty about which jokes you're allowed to make and which you aren't (though there's one running gag, in which a squaddie mocks a dead American and is persistently told that it's too soon, that one infers was generated by the writing process.

"A suicide bomb? Would that be funny, if it only got adults?" "Too soon.") It's by the Miranda writing team, and has that distinctive worldview in which people are basically nice, and the comedy comes from the degrees of absurdity by which that niceness is manifested. And, like Miranda, a lot of its watchability comes not from actual laughs, but from enjoying the company of the nice people. Inevitably, however, this means that it never gets anywhere near the bone, and has none of that wincing discomfort that has one, while watching Peep Show or The Thick of It, literally drawing away from the telly, crying. While on the one hand it feels unfair to judge all comedy by the best of it, I sometimes think television could apply some industry standards, and learn from itself, like science.

Some joke structures persistently don't work; they clank along the ground like an exhaust pipe falling off a van. I'm thinking in particular of the Socratic school of joke, demonstrated here when phlegmatic and likable Katie Lyons (playing a soldier called Bird) hefts down the material for this exchange like a scree: "So you've never named anything?" she asks another soldier. "Nothing except my cock, which is called Andy McNab." "Why would you name your cock Andy McNab?" Because of all the action it's seen ... because it would survive on nuts and berries ... because it's full of bollocks ... I'm paraphrasing but, seriously, it's only one rung above a knock-knock joke. In short, it could be harder on itself, and harder on the viewer, and probably a bit harder on the cast, and we would still like it, and maybe love it.

"Too soon?" one character asks in ­Bluestone 42 after he makes a tasteless quip about the death of a CIA officer. That's the question you might be asking after watching BBC3's new sitcom about a bomb disposal team in Helmand Province. After all, it's usually polite to wait until a war is actually over before you start making jokes about it.

The Korean War had been done and dusted for more than 20 years before M*A*S*H waded in. The same goes for Dad's Army, while Blackadder Goes Forth waited a good 80 years for the dust from the First World War to settle.

And after the number of documentaries the BBC has made about Afghanistan - in particular Our War, also on BBC3 - the show's writers will have been acutely aware of the potential offence they could cause by making comedy out of conflict. It seems their main concern was getting all the military details right, rather than whether they should be making it at all.

But, putting all thoughts of whether Bluestone 42 is wildly inappropriate or not to one side, thank goodness that it's actually very funny, with an excellent line in banter.

Oliver Chris is perfectly cast as Captain Nick Medhurst - the officer who fancies himself a little too much as the dashing war hero, and expects the new female padre (Hustle's Kelly Adams) to feel the same.

The big ensemble cast also includes Tony Gardner (Lead Balloon and Fresh Meat) as the Lt Colonel, Katie Lyons as the blokeish Corporal Bird and a bomb-seeking robot called Arthur.

It's BBC3's most successful sitcom ever, so of course it's back for series two. Writer Stefan Golaszewski's low-key, handily low-budget visits to the flat inhabited by laid-back Steve (Russell Tovey) have barely changed, with the main development being that Steve's sexy, tolerant girlfriend Becky (Sarah Solemani) has moved in, not that she's got round to unpacking much.

Interrupting their regime of toast, sex and lying about are the friends and family who bring the funnies in from the outside world. They're lazy smiles rather than belly laughs, making this a show that requires your mood to match its own - but Steve's ex Julie (Katie Lyons) dropping in, this series promises a bit of drama, too.