THE PRESIDENT of the United States seduces an impressionable teenage girl. White House spin-doctors rush his career into ER, and advise him to distract attention from the scandal by manufacturing a foreign war - with Albania, a faraway country about which he knows little.

Since Barry Levinson's Wag the Dog (15) opened in America last December, the Lewinsky affair, the Iraqi stand-off and the Kosovo crisis have earned it a precognitive pedigree that puts Nostradamus back in the Mystic Meg league. Some of the film's gags are supernaturally specific (script by David Mamet). Your jaw hits the floor when one of Levinson's cod news bulletins flashes up a photograph of the President and his teenage trick that is almost indistinguishable from that famous image of Bill and Monica being affectionate in front of a barricade. Elaborate conspiracy theories have been based on less.

Refreshingly, Levinson's crisis managers are not a cabal of Ray-Banned G-Men. Instead, they're a gaggle of media types, headed by fixer Conrad Brean (Robert De Niro, in the tweeds and dickie of a comic TV pathologist), presidential aide Winifred Ames (Anne Heche, a smart actress underused again) and Stanley Motss (an ice-cream-quiffed Dustin Hoffman), a movie producer who once remade Moby Dick "from the point of view of the whale". Their campaign eschews expensive missile strikes and big-budget militarism for something more cost-effective - a PR circus for a conflict that isn't actually happening. They plant rumours, they produce a plausible war hero (who, due to a clerical cock-up, turns out to be a psychopath who has been jailed for raping a nun), and they commission a "We Are the World"-type theme song from a knackered C&W artist (played by knackered C&W artist Willie Nelson). Jean Baudrillard, who famously argued that the Gulf War didn't really take place, should be laughing like a drain that doesn't exist.

Shot on a breakneck 29-day schedule (while Levinson took time off from Sphere), Wag the Dog combines the hand-held zippiness of reportage with the heavyweight presence of two of Hollywood's wittiest performers. Its coincidence with actual events both sharpens its bite and reminds you that today's satire is tomorrow's government policy. Bill Clinton has succeeded this week in getting Monica Lewinsky off America's front pages by announcing that his pet dog Buddy is for the genital chop. Vets' bills aside, it seems that the White House has hit upon an economical way to distract media attention from the inmate of the presidential pants. Bill seems to have bested Bob De Niro - a fictional war with Albania might be pretty smart politicking, but a plan to sacrifice canine gonads rather than American soldiers is indisputably the dog's bollocks.

I was baffled by As Good As It Gets (15). Too abrasive to be romantic comedy, too flimsy and farcical to make the grade as proper drama, its plot has the taste of popcorn: Melvin, a misanthropic novelist, finds redemption through the love of a single mum and her asthmatic boy, a gay neighbour, and a cute dog. And for its first hour, James L Brooks's film does little to suggest that it will transcend the poverty of its synopsis.

The routine goes like this: Jack Nicholson's Melvin dispenses a discouragingly unfunny round of un-PC put-downs. (The best, perhaps, is his response to a female fan who asks him how he writes women characters so well. "I think of a man, then I take away reason and accountability," he explains, with devilish politeness.) Helen Hunt's embattled Carol provides him with a feisty foil. Greg Kinnear's Simon embodies a tired collection of gay cliches (bleachy hair, flouncy shirt, lapdog fixation, artistic bent, and shades hanging from the neck of his T-shirt). And Verdell the dog cocks its leg in inappropriate places.

But if you watch an amoeba for long enough, it will eventually evolve into Richard Dawkins. And that - loosely - is what happens during the course of Brooks's movie. Its massive 219 minutes give the cast plenty of time to breathe a strange kind of life into variable material. Hunt, for instance, bristles with so much tough good humour and plausible thirtysomething angst that she brings genuine unease to the inevitable romantic conclusion.

At 51, Nicholson now looks like a Satanic idol sculpted out of chipolatas. But he can still invert those diabolic eyebrows with impossible ease, gather the flanks of his gravy-tanned face, and allow you to luxuriate in his badass, boss-eyed, irresistible ugliness.

Melvin's transformation from miser into boyfriend and dog-sitter proceeds at a plausibly slow pace. Instead of saving it up for a concluding frenzy of humility, Brooks has crafted the first variant on the Scrooge story to stick around for the cold turkey: Melvin has paid the medical bills for Hunt's Tiny Tim-like son before the movie's first hour is ended, but Brooks keeps the story going for reels longer. He might be over-fond of

dog-wee jokes, but this willingness to follow a well-worn tale beyond its usual moment of closure makes a point rarely offered by the standard Hollywood output - that there's more to rejoining the human race than showcase acts of generosity.

Fallen (18) also attempts to transform familiar territory. It's a serial- killer thriller in which the culprit isn't just some psycho with RSI in his cleaver-hand, but a demon who can leap from host to host like Beelzebub's own headlouse. This winningly creepy device turns much of Gregory Hoblit's movie into a tag-game, in which the majority of the cast - from stars to walk-ons - get their shot at the Nicholsonian snarl of demonic possession. On the side of the angels, Denzel Washington plays detective John Hobbes, whose latest case has him consulting a glamorous lady theologian (Embeth Davidtz) and digging through dusty demonological tomes. (Though since he has to ask a nun what the word "apocalypse" means in the last half- hour of the film, his research methods can't be very rigorous.)

The recent Keanu/Pacino Old Nick flick The Devil's Advocate cheekily associated Satanism with lesbianism, incest and bourbon on the rocks. But Fallen is free of such vices. The nearest this devil gets to a bona fide perversion is a taste for Mick Jagger and for cornflakes. And Washington remains decorously chaste - possibly because Hoblit wants us to see him as a saintly figure, or perhaps because Hollywood is still nervous about inter-racial romance.

Instead, human frailty is represented by the appetites of Hobbes's lardy colleagues (John Goodman and James Gandolfini), who swill coffee, neck doughnuts, devour chicken legs and fill the screen with their prodigious bottoms. If this isn't a steal from The Fast Show's Fat Sweaty Coppers, then it owes something to David Fincher's portrayal of the sin of gluttony in Se7en - a film whose forensic Gothicism Hoblit has studiously duplicated. He treats us to the same dark iconography of grimy light-fittings, tallowy light, rainswept window panes and grime-swashed wallpaper. And despite that lack of originality, Fallen is the most effective variation on this theme so far. Perhaps that has something to do with the associations of the director's name. As Professor Quatermass would tell you, a Hob is a medieval demon, by which any self-respecting Satanist would be pleased to be possessed.

Cinema details: Going Out, page 10.