No Man's Land (15); <br></br>The Closet (15); <br></br>I'm Going Home (PG); <br></br>Happy Man (NC)

No Man's Land begins with men stumbling through a midnight fog, but even when the Sun rises and reveals their whereabouts – a lush green valley – they remain to all intents and purposes benighted. For this is Bosnia, June 1993, a country in the grip of a civil war that nobody appears to understand, where the peace of a summer's day can be suddenly shattered by artillery fire. Two soldiers, a Serb and a Bosnian, find themselves stranded in a trench between opposing front lines, and through the story of this strange meeting the writer-director Danis Tanovic coolly addresses not only the intractable nature of the conflict but also collateral issues of peace-keeping and media interference.

At first the soldiers taunt one another in schoolboy fashion. The Bosnian, Ciki (Branko Djuric) forces his Serbian adversary Nino (Rene Bitorajac) to admit that his side are to blame for starting the war. "Why should he," asks Nino. "Because I have a gun and you don't," Ciki replies, unanswerably. Though both men are carrying wounds, they are still in better shape than Ciki's comrade Cera (Filip Sovagovic), who was caught in the same blast and presumed dead; instead he has woken to find himself attached to a land mine that will explode if he is moved. Such is the inventive malignity of modern warfare. Eventually, after Ciki and Nino wave a white flag from the trench, UN forces begin to investigate, a pushy TV news journalist (Katrin Cartlidge) sniffs a story in the making and a three-man siege turns inexorably into a three-ring circus.

The tragedy we can see unfolding is rendered even more acute by the film's insistent strain of absurd black farce. It's signalled early on when a soldier, ensconced in a newspaper, shakes his head and sighs, "What a mess in Rwanda". Tanovic may well have had the anti-authoritarian satire of M*A*S*H on his mind (a link made the stronger for the bespectacled Bitorajac's resemblance to Radar), though his experience as a documentary-maker has also equipped him in terms of understanding the way bureaucracy encumbers the route to peace. There's an especially poignant moment between Nino and Ciki when it transpires that they knew the same blonde in Banja Luka, and we glimpse the possibility that, in another, happier time, these two might have been friends. Not everyone's a villain here – a French UN sergeant (Georges Siatidis) makes a genuine effort to unpick the knots of antagonism – but the tenor of this darkly impressive film suggests he's pursuing a hopeless cause.

Considering its five star cast (Daniel Auteuil, Gerard Depardieu et al) French comedy The Closet ought to be premier cru but tastes disappointingly like vin ordinaire. Writer-director Francis Veber, who had a mighty hit with Le Diner de Cons, sets up the premise quite nicely: Francois Pignon (Auteuil) is a middle-management drone who learns that he's about to get fired, but on the advice of his new neighbour (Michel Aumont) develops a survival strategy. He allows an office rumour to be started that he's gay, thus stymieing his boss, who now won't dare sack him for fear of seeming anti-homosexual. The idea is that Pignon's private life transforms him from nonentity to "interesting" outsider; what's more, he wins the respect of his once indifferent son and the curiosity of his ex-wife.

Sadly, the film gets into a tangle when a double-bluff started by the personnel manager (Thierry Lhermitte) convinces homophobic brute Santini (Depardieu) that he's going to get sacked unless he cosies up to Pignon. Cue awkward attempts at friendship and unwarranted acts of generosity (a pink cashmere sweater for Pignon's birthday), the upshot of which is a seesawing plot of triumphs and reversals that are unlikely and, worse, unfunny. Auteuil and Depardieu are too skilful to be thrown by the implausibilities, but one can't help feeling that Veber's screenplay needed some careful rewrites: what promises to be a droll parable on sexual hypocrisy instead declines into a limply feel-good story of a worm that turned.

Always good to see Michel Piccoli – his death scene in Les Choses de la Vie (1969) is never to be forgotten – though his features these days look set in an attitude of melancholy exhaustion. In Manoel de Oliveira's I'm Going Home he plays Valence, a grand old stage actor who has recently lost his family in a road accident, leaving only a young grandson as his heir. His cares aren't lightened by an agent who keeps offering him lucrative rubbish on TV. Few cameras stare so intently at things as de Oliveira's, and the long excerpts he films from Ionesco and The Tempest are frankly de trop, but this patient detailing of an actor's life – a portrait of the artist as an old man – has a fascination akin to watching a sun slowly disappear beneath the horizon.

The title Happy Man rings with a bleak irony. Malgorzata Szumowska's directorial debut is a glum study in spiritual lassitude, its protagonist a young man (Jadwiga Jankowska) with vague aspirations to be a writer but all the drive of a novocained haddock. Then, on learning that his mother is dying of cancer, he decides it's time he married and moved on. The consequences of this new-found purpose are anything but hilarious. Szumowska nods to her Polish compatriot Kieslowski in the slow accumulation of detail, enigmatic silences and crepuscular atmosphere; the result is the polar opposite of a fun night out.