(PG-13) 2 1/2 stars “Why do they hate us?” That’s been a recurring question on a lot of American minds for the past couple of years or so. And during that same period of time we’ve had a president whose answer to that question can be boiled down to a single word: envy. Envy is also the name of the new Barry Levinson film starring Ben Stiller and Jack Black. The fact that the subject matter of Levinson’s film and our president’s explanation for the rest of the world’s sinking opinion of us happens to coincide does not appear to be an accident. For Envy (the film) is a satiric fable whose dark humor seems aimed at a larger, more telling meaning about who we are now. The story revolves around two middle-class friends played by Stiller and Black. They work for the same sandpaper company (3M, in what has to be one of the weirdest examples of product placement in movie history) and live across the street from one another in a scorched suburban landscape dominated by enormous, high-tension power lines. Black’s character, Nick, is a budding inventor who comes up with the idea for a product that makes dog turds evaporate — “Vapoorizer.” The idea seems so ridiculous that Stiller’s character, Tim, refuses to take him seriously — until, that is, Nick winds up making millions of bucks which makes Tim sick with … envy. Suddenly, Nick isn’t just rich — his life becomes like one of Fellini’s wilder fantasies. On the suburban cul-de-sac where his house once stood is now a mansion that would make Citizen Kane blush. Overnight, his children become concert pianists, he is surrounded by simpering servants and his white stallion grazes on the apples growing on Stiller’s tree across the street. All of this makes Stiller desperate with resentment. Before long he’s blown a fuse at work and lost his job. To make matters worse, he is befriended in a bar by a long-haired stranger, the “J-Man,” played by Christopher Walken. Walken seems to have become a kind of icon for everything crazed and countercultural about this country today. He is, as usual, terrific. Which is more than can be said for this ambitious muddle of a movie. In Nick the inventor, Levinson seems to be reaching for a big American metaphor. This country, after all, was an invention, a wild, free-thinking idea driven by the best of intentions. That it would be overtaken by vulgar decadence and subverted by those it wanted most to love and bring along for the ride can, according to Levinson, be understood in terms of a human frailty that might still be redeemable. Not a bad premise for a contemporary Hollywood comedy. But Levinson trusts neither his audience nor his concept. And so he undercuts the power of his metaphor through the trivializing insertion of a literalistic singing commentary, and clutters the story with parenthetic sidetracks, like a trip to sell Vapoorizer in Italy, that are as conceptually half-hearted as they are distracting. Barry Levinson appears to understand that our current politics is a symptom, not the source, of what feels so unbalanced about this country today. But Envy may, at most, go down as a rough draft on the road toward trying to get to something like a kind of truth.