How do you solve a problem like Von Trier? The Danish provocateur delights in duping the media into fulminating against his latest scurrilous ruse and revels in the blazes of publicity that attend each pronouncement or prank. Yet when he is not placing himself in the centre-stage spotlight, Lars von Trier is a fine film-maker. Indeed, as the co-author of the Dogme 95 Manifesto, he has shown himself to be an artist who cares as much about his medium as the wealth and celebrity it generates.

Thus, while it's impossible to overlook completely the foolish remarks about Nazism made at this year's Cannes Film Festival, Von Trier should be judged less on wild statements made in the heat of the moment and more on films like The Element of Crime (1984), Europa (1991), Breaking the Waves (1996), The Idiots (1998), Dancer in the Dark (2000), Dogville (2003) and The Five Obstructions (2003) that have challenged audiences with their contentious themes and incidents and pushed the boundaries of cinema itself with their refusal to be bound by the conventions of either the classical Hollywood narrative or the auteur aesthetic. However, he has excelled himself with Melancholia.

Von Trier has long suffered from crippling bouts of depression and he seemed to hit rock bottom in his depiction of a hopeless humanity in Antichrist (2009). But, even though this intense melodrama teeters on the brink of Armageddon, it is much more accepting of our flaws and fragility and, as a consequence, it makes death and destruction seem less daunting, if still hardly desirable.

The action gets off to an unforgettable start, as Wagner's Tristan and Isolde plays on the soundtrack over a chillingly beautiful montage of surreally supernatural images connected to the impending collision of the planet Melancholia with Earth. At their centre is Charlotte Gainsbourg, who seems to be sinking into a golf course while carrying her son, and sister Kirsten Dunst, who endures a shower of dead birds, stalks through a dense forest in a wedding dress and floats in a murky pond before extending her arms to allow jagged shards of electricity to fizz between her fingertips as a portent to the cacophonous explosion that signals the end of the world After eight intoxicatingly excruciating minutes, these carefully controlled compositions give way to handheld viscerality as Von Trier cuts to Dunst and new husband Alexander Skarsgård sitting in a stretch limo struggling to navigate the narrow, winding road leading to the country hotel run by Gainsbourg and husband Kiefer Sutherland. Although this is supposed to be her happiest day, Dunst is sorely troubled by anxieties that Gainsbourg strives valiantly to keep in check, as divorced parents John Hurt and Charlotte Rampling exchange barbed insults and Dunst's advertising agency boss, Stellan Skarsgård, pesters her for the tagline of an important new campaign.

However, as wedding planner Udo Kier discovers to his increasingly frazzled cost, Dunst is a manic nightmare to organise and she even exhausts her groom's patience as she disappears into the woods to answer a call of nature, decides to have a bath just as the cake is going to be cut and then abandons the bridal suite to roll around in a bunker with Skarsgård cousin Brady Corbet. By the time Dunst returns, everybody has gone (including her spouse) and she and Gainsbourg clear their heads by galloping through the grounds in the early morning mist - although Dunst still manages to notice that something significant has happened in the sky.

The focus is supposed to fall more on Gainsbourg in the second half of the film, which takes place a few weeks later. She is terrified by the growing threat of Melancholia and is busy trying to ensure she and son Cameron Spurr can survive the implosion. Sutherland is a disaster denier and confidently predicts that the entire scare has been whipped out of all proportion by the media. As for Dunst, she spends much of her time bathing in the rays from the approaching sphere and becoming increasingly sanguine about the whole business. Even when Sutherland commits suicide on realising that his scepticism has been misplaced, Dunst continues to acquiesce in a consummation devoutly to be wish'd.

Given that the opening gives away the inevitable denouement, this is less a work of science fiction than a philosophical treatise on the insignificance of mankind and the futility of existence. It may not be as profound as Terrence Malick's The Tree of Life, but, despite the odd purple passage or deliberately incensing outburst, it also avoids being trivial. Moreover, it very much chimes in with the director's previous pictures and their preoccupations, with Dunst and Gainsbourg being flipsides of the typical Von Trier anti-heroine, who manages to survive the slings and arrows hurled at her without quite knowing why she has been spared. Only these sibling perish along with everyone else in the depressive's ultimate revenge on his critics.

Manuel Alberto Claro's photography and Jette Lehmann's production design are faultless. But the performances are also remarkable. Hurt and Rampling are hilarious as the genial johnny and the embittered bitch, while Stellan Skarsgård archly lampoons the breed of advertising executive who not only thinks that everything's for sale, but that everything can be sold. Sutherland is slightly sold short with the role of a pompous prig, whose cocksure boasting during the wedding breakfast he has stage-managed at such effort and expense giving way to a rather clichéd cowardice. But Dunst and Gainsbourg are superb and although the former won the Best Actress prize at Cannes, it is the latter's sympathy for her near-catatonic sister in the midst of her own unbearable torment that gives the occasionally implausible and often self-consciously Chekhovian doomsday scenario its heart and soul.

The misdeeds are anything but apocalyptic, but the setting is just as sublime in Jacques Deray's simmering 1969 study of lust, envy and revenge, La Piscine. Opening like one of Claude Sautet's piercing dissection of bourgeois mores and gradually evolving into a Chabrolian thriller, this is a film long overdue rediscovery and Park Circus must take great credit for returning it to theatres rather than releasing directly to disc. Let's hope there are plenty more similarly delicious pleasures to come.

Blocked writer Alain Delon has taken a summer let on a friend's house in the South of France to work on his relationship with girlfriend of two years, Romy Schneider. They lounge around the pool under the scorching Mediterranean sun and tease each other with meaningful glances and calculated words that suggest their intimacy while also betraying that the first flush of passion has cooled. Indeed, they are both somewhat relieved when Delon's old buddy Maurice Ronet shows up out of the blue with his 18 year-old half-English daughter, Jane Birkin.

But, while they speculate about the nature of their guests' relationship, Delon begins to allow his eyes to rove over the sunbathing Birkin, while Schneider withholds the fact that she was Ronet's lover long before he supposedly matchmade them as Delon's pal. The tension mounts in the most urbane manner, most notably during a sequence in which music producer Ronet plays the assembled a disc by his latest star. But the all pretence of civility is shattered when Ronet returns from a drinking session in the nearby town with some 30 revellers, who proceed to have a party that convinces Delon that Schneider is keeping secrets and that his best form of hurting her lies in seducing the pouting Birkin.

Ronet realises what Delon is planning and confronts him beside the pool. The argument gets heated and Ronet accidentally falls into the water. But, instead of fishing him out, Delon facilitates his drowning and speedily arranges things to look as though Ronet had perished during a midnight dip.

Birkin is surprisingly unmoved by her father's demise and Delon thinks he has committed the perfect crime. After the funeral, however, he is visited by Paul Crauchet, an inspector who suspects that the garden scene seemed a touch too neatly arranged and his dogged pursuit of clues puts increasing strain on Delon's now fraying relationship with Schneider.

With Jean-Jacques Tarbès's Hockneyesque ravishing images glinting to the refined tones of Michel Legrand, this is an impeccably placed insight into the psychology of couples who are no longer in love. The deft shifts between close-ups and eyeline matches expose the raw emotions experienced by Schneider and Delon as Deray exploits the perfidious power of a silent gaze. But, while Deray and Jean-Claude Carrière's screenplay is as subtle as the performances, the plot matters less than the psychological insight, which acquires a cunning subtext due to the fact that Delon and Schneider had only recently broken off their real-life engagement and that Delon had also murdered Ronet in Plein Soleil (1960), René Clément's exceptional reworking of Patricia Highsmith's The Talented Mr Ripley.

Deray's restraint is crucial to the story's creeping sense of unease. However, holding back is an alien concept to Japanese cult director Sion Sono. Following Love Exposure (2009) and Cold Fish (2010) in the loosely linked `Hate Saga', Guilty of Romance is packed with Sono's trademark fetishes, flourishes and flaws. Once again taking a true story as its inspiration, this multi-chaptered mélange of pinku-eiga, film noir and kitsch melodrama peddles the blend of aesthetic audacity, philosophical bleakness and borderline misogyny that has previously divided opinion over Sono's highly distinctive offerings.

Sôhei Tanikawa's photography eerily captures the tacky, neon-lit colours of Yoshio Yamada's garish production design, while Yasuhiro Morinaga's piano and cello score lends a note of melancholy. But this disturbing and often lurid dissection of human foible will earn the Japanese auteur few new fans.

Fresh from an energetic tryst at a Tokyo love motel, cop Miko Mizuno arrives at a crime scene with walls daubed with gouts of fluorescent pink paint to discover a mutilated female corpse that has been rearranged with spare parts from a mannequin. Her investigations soon bring her into contact with prim housewife Megumi Kagurazaka and eminent academic Makoto Togashi.

Kagurazaka is married to erotic novelist Kanji Tsuda, who keeps to a strict routine and has little time for his wife when he finally returns home precisely 12 hours after he left. Consequently, she takes a job in a supermarket and, typically, lands a job on the sausage counter. Bored with the menial chores, Kagurazaka is persuaded by Togashi to become a nude model and, having overcome the initial shock of both stripping and interacting with her co-stars, she becomes seduced by the alien feeling of being wanted and admired and eventually throws herself wholeheartedly into the prostitution that Togashi finds so liberating - as nothing gives a woman more power than charging a man for sex.

This dubious premise is destined to lead to trouble. But Kagurazaka can't resist the challenge of donning a red wig to vamp the oblivious Tsuda and then play the dutiful spouse at home. Togashi's mother Hisako Ohkata is no more aware of her daughter's secret life or her long-suppressed issues with her father. But the endless deceptions only slow Mizuno's inquiry (along with her frequent bouts of phone sex out of earshot of her husband and son), although most will spot the milquetoast murderer on first sight.

When not assaulting the audience with lashings of blood, paint, flesh, lust and violence, Sono occasionally pauses to drop an arch literary reference and insert another bizarre Belle de Jour-like twist. But, despite chapter headings like `The Castle' and `The Enchantress Club', there's no escaping the fact that this is more a work of exploitation than art, with more emphasis being placed on pornography than plausibility. Kagurazaka, Tsuda and Mizuno deliver dauntless performances and Sono stages the graphic action with grotesque panache. But the humour feels mocking rather than knowing and the whodunit gets lost in the prurience.

Brit Simon Rumley delves into the depths of American depravity in Red, White & Blue, a decidedly brutal outing that starts out as a disturbing study of moral abnegation and ends up deep in slasher territory. Definitely not for the faint-hearted, this is another trenchantly unsettling work by a director with a keen sense of cinema and a very high tolerance for humanity's baser instincts.

Working as a cleaner in order to afford her lodgings, Amanda Fuller is forced to find alternative employment when she's duped by her grasping landlady. Always ready to dress provocatively and sleep with any man who takes her fancy, Fuller plays by her own rules. Consequently, she wants nothing to do with new tenant Noah Taylor, a recently discharged Iraqi veteran whose dishevelled mien, deliberate manner and self-proclaimed loathing of animals she finds creepy.

However, he proves to be the only one who cares for her after she is gang-raped by aspiring musician Marc Senter and bandmates Nick Ashy Holden, Patrick Crovo and Jon Michael Davis. But not even Taylor can protect her when Senter discovers he is HIV+ and that he has infected his mother, Sally Jackson, who has been receiving his blood in regular transfusions during her successful battle against cancer.

With Fuller's murder and dismemberment taking place off screen, this bitter domestic twist represents the picture's most shocking moment, as while Taylor's pitiless revenge spree is depicted with chilling slickness, it lacks the unspeakable awfulness of this grim revelation. As a former critic, Rumley is sufficiently versed in Larry Clark and Wes Craven to discomfort the viewer during the nymphomanic and psychopathic sequences. But the abrasively vulnerable Fuller's struggle to come to terms with her juvenile traumas is always more intriguing than the Taylor's methodical rampage.

A tendency towards melodramatics and a shortage of empathetic characters similarly afflicts Sallie Aprahamian's Broken Lines, as London waitress Doraly Rosa feels obliged to stand by stroke victim boyfriend Paul Bettany, while also being tempted by upwardly mobile property developer Dan Fedenburgh. Neither man is worth her pity, let alone her love. But she soon finds herself unable to leave either.

Rosa meets Fedenburgh when he comes into her cousin Nathan Constance's café after fleeing his tailor father's funeral. Her earthy empathy strikes more of a chord with him than bourgeois fiancée Olivia Williams's pretty phrases and he invites her to his father's old shop and quickly becomes besotted. Moreover, he realises that he can see Rosa nursing Bettany from an upstairs window and he spends more time spying on her than he does helping Williams plan their imminent wedding.

Ex-boxer Bettany also begins to suspect when Rosa rushes out into a rainy night to tell Fedenburgh that she can't keep their date at the local greyhound track and aunt Rita Tushingham also becomes concerned that she risks losing the little she has if she persists in playing with fire. Following a day trip to the coast, Fedenburgh and Rosa finally become lovers. But, while he tries to summon up the strength to break up with Williams, Rosa becomes increasingly guilty at cheating on Bettany, even though he is aggressively manipulative and can offer her nothing but drudgery and dependence.

Working from their own script, Fedenburgh and Rosa occasionally generate sparks. But this is a ponderous melodrama that struggles to accommodate its Jewish subtext and finds far too little for the more marginal characters to do. Sequences like Fedenburgh's half-hearted attempt to patch things up with estranged mother Harriet Walter feel as extraneous as the birthday party for Williams's father (Nicholas Le Prevost) and Bettany's overdue return to the gym to see a buddy he has been avoiding. Jean-Louis Bompoint's images of the dark interiors of the tailor's shop are atmospheric and he and Aprahamian catch the spirit of Finsbury Park. But this lacks conviction as a study of class and ethnicity, while Bettany's angry excesses expose the tepidity of the other performances.

We end this week with two contrasting stories from Iran and Afghanistan. The first is a noble project whose courage and trenchancy is undermined by mediocre execution, the second is less ambitious, but infinitely more accomplished, personal and poignant.

Regular readers of these pages will be familiar with the theory that Iranian film-makers have long been fashioning a `cinema of moral anxiety' similar to the one that emboldened the Polish people in the late 1970s. Indeed, Ali Samadi Ahadi's The Green Wave hints that the Green Revolution - like the Solidarity uprising before it - may simply be the false dawn before the brand new day.

Ahadi examines the events surrounding the disputed Iranian election in 2009 through a mixture of interview, archive and animation. Opting for more of a graphic novel look than Vincent Paronnaud and Marjane Satrapi's Persepolis or Ari Folman's Waltz With Bashir, this is an ambitious attempt to use personal testimony, blog entries, Twitter messages and home movie footage to show how President Mahmoud Ahmadinejad relied on force to cling on to power after thousands took to the streets in support of opposition candidate Mir-Hossein Mousavi. However, a mawkish score by Ali N. Askin, the manipulative monologues and some undistinguished graphics detract from the film's power.

Ahadi centres his account on fictional students Azadeh and Kaveh, who are voiced respectively by Pegah Ferydoni and Navid Akhavan. Azadeh is rather caught up in events after the Mousavi stadium speech that launched the Green Revolution, but Kaveh works for his campaign team and finds herself in the eye of the storm as support for change grows and people of all ages and backgrounds demonstrate on the streets with an unprecedented boldness and enthusiasm.

However, following the announcement that Ahmadinejad had won 69% of the poll, the reprisals began, with security agents riding through Teheran on motorbikes to administer beatings and snipers firing on the crowds and infamously killing defenceless protesters like Neda Agha-Soltan. Both Azadeh and Kaveh are arrested and they chillingly recall the harsh treatment they received and the brutality they saw being inflicted upon others. But, despite the sobriety of Alireza Darvish's artwork, Sina Mostafawy's animation struggles to convey the full horror of the pitiless violence with the same viscerality as Barbara Toennieshen and Andreas Menn's live-action montages.

Nonetheless, Ahadi makes solid use of eyewitness accounts by journalist Mitra Khalatbari, lawyer Shadi Sadr, activist Babak, ex-militiaman Amir Farshad Ebrahimi, blogger Mehdi Mohseni, Shiite cleric Mohsen Kadivar, Nobel Peace Prize winner Shirin Ebadi and former UN war crimes prosecutor Payam Akhavan. But their considered accounts only emphasise the emotive content of the voiceovers and the agit-prop nature of the graphics. Consequently, while this provides an accessible account of the anti-Ahmadinejad fervour and the severity of the crackdown, it fails to explore the reasons for the popular uprising and the extent to which the West's obsession with Iran's nuclear ambitions has deflected attention away from the dictatorship's barbaric crushing of dissidence.

In 2002, documentarist Phil Grabsky made the acquaintance of an eight year-old victim of Taliban injustice and told his story in the deeply moving profile, The Boy Who Plays on the Buddhas of Bamiyan. Over the course of the following decade, Grabsky made periodic returns to Afghanistan and the transformations that have been wrought in both the lad and his homeland are revealed in The Boy Mir - Ten Years in Afghanistan, a chronicle that conveys the implacability of the landscape and the indomitability of its inhabitants and suggests that there is cause for cautious optimism behind the grim headlines.

When Grabsky first catches up with Mir in February 2003, he is relieved to discover he is still alive and still relatively safe in the cave network that had grown up around the once-loved religious site 143 miles north-west of Kabul. Living with father Abdul, mother Murwarid, half-brother Khushdel and his wife Gulafrooz, Mir makes light of the grinding poverty and freezing temperatures that force them to scrap with their neighbours for the warm clothing donated by aid workers. But when the family fails to get one of the 100 houses built in the valley by foreign charities, it has no option but to return to its village in the north and hope that the prejudice and drought that had compelled it to flee have dissipated.

With Abdul unable to work after being injured in a mining accident, the burden of providing for his not always grateful kinfolk falls on Khushdel, who uncomplainingly takes any job going. Mir is also keen to do his bit and he herds goats and tends to a couple of donkeys to bring in some money. However, his chores often keep him away from school and the family is divided about the value of his education when his income is so vital to its survival. Abdul knows that Mir's only chance of bettering himself - and, thus, ameliorating their situation - lies in securing qualifications and a lucrative profession. But good intentions are invariably the first thing to be sacrificed in the face of pressing daily need and Mir is soon shovelling coal from the nearby mine with his pals for a share of a meagre $40 per day.

His spirits remain high, however, and he plays up to Grabsky's camera as he takes a wash and plays with his friends, with girls in chadors joining in a game of football that is shown to the accompaniment of radio headlines about the ongoing war that seems to be happening a million miles away from this remote haven. Grabsky reveals that the cost of the conflict has risen to $300 billion by 2007 and yet only a tenth of that sum has been set aside for aid. Consequently, the 13 year-old Mir has to skip the lessons vital to his ambition to become a teacher in order to join Khushdel down a mountainside mine, where he helps load coal into sacks and lead the encumbered donkeys through perilous passages to the surface.

The effort seems worthwhile when the siblings earn enough to repair the roof of their humble shack and even put in a window. But cash is so short that Mir has to join other hopefuls in competing for prizes in the foot races staged by Nasim, a local entrepreneur who splashes his largesse with a mix of benevolence and braggadocio. Yet, by the time Grabsky returns in 2008, Mir and Khushdel have begun farming a small patch of land and Mir even has enough money to buy a bicycle (albeit one with no brakes). On the distaff side, tensions are increasing at home, with Abdul and Murwarid bickering constantly and Gulafrooz complaining that Khushdel is lazy and deprives her of the bare necessities, let alone any small luxuries to make her feel wanted.

Given such ingratitude, it's impossible not to feel sorry for Khushdel and Mir as they share a cave in the hills so they can be closer to the fields and the livestock they tend. Mir hardly ever attends classes now and his future seems as uncertain as that of the country, as Grabsky informs us that corruption and crime are on the rise and that the Taliban insurgency has inflicted mounting casualties on Allied and Afghan forces and driven the cost of the enterprise up to $500 billion. The teenager sits in on a meeting of his elders, as they lament their misfortune and those opining that things are slowly getting better are shouted down by those who still view Imperialist England (which many believe is a part of the United States) as the Great Satan.

By the time Grabsky revisits the village in July 2009, however, the evidence of improvement is hard to refute. Mir has spent $250 on a motorbike, while Khushdel has a mobile phone that makes it much easier to do business and provide for the family. Indeed, the miners have even clubbed together to buy a generator and Mir giggles at the belly dancer on the television in the recreation tent as he finally becomes aware of a wider world away from his isolated home. But grim reminders of the reality of living in a war-torn state are never far away, as armoured vehicles patrol the region (and patronisingly leave the residents notebooks as a goodwill gesture) and Mir recalls the sadness that afflicts everyone when the body of a fallen hero is returned for burial.

Abdul is adamant that Mir will never join the army. But he continues to prevaricate over the value of his education. Thus, as Grabsky departs in the summer of 2010, Mir is still labouring more often than studying. Moreover, he has started to wonder why foreign forces are still on his land and is beginning to question whether they have actually had a beneficial impact. The answer can be see in the patches of greenery in the forbidding mountainscapes and in the trio of television sets that now keep the villagers informed and entertained. But it must be difficult to appreciate such progress when working every waking hour and then listening to one's parents insulting each other into the night.

Grabsky concludes with the understandable concern that such precarious stability will be jeopardised by the eventual withdrawal of international troops. But he imposes no political spin on this compelling snapshot of the rebirth of a nation. Indeed, he allows the garrulous Mir to speak for himself and his determination to have a happy youth in the face of so many trials is deeply humbling. As one would expect, given the conditions in which the crew toiled, the footage is of a variable quality and Grabsky and editor Phil Reynolds occasionally have to work hard to maintain a cogent narrative thread. But the fact the film has been made at all represents a remarkable achievement and one fervently hopes that further instalments detailing this unique friendship will emerge in ensuing years.