Paradise Now (15) <!-- none onestar twostar threestar fourstar fivestar -->

Hany Abu-Assad's Paradise Now would make a good double bill with the recent documentary Diameter of the Bomb, if two films about suicide bombing could be endured back-to-back. While the latter concentrated on the victims of a bus bomb in Jerusalem, the former focuses on what it takes to be a perpetrator. Could anything bleaker be imagined?

Oddly, the movie begins almost lightheartedly in its portrayal of a friendship. Khaled (Ali Suliman) and Said (Kais Nashef) are two young Palestinians who work as car mechanics but much prefer drinking tea and getting stoned on the hillside overlooking the West Bank city of Nablus, where daily life is hemmed in by Israeli checkpoints and occasionally interrupted by a rocket blast. A young woman named Suha (Lubna Azabal) brings in her car for repairs and strikes up a rapport with Said, who confesses that his life is pretty "boring". Unfortunately, life gets all too interesting when a militant cell contact Said and Khaled and inform them they've been chosen for a suicide mission in Tel Aviv. With a sense of horrified surprise we learn that the two friends have prepared for this moment for years - years dominated by an occupying regime that has left them impoverished and practically hopeless.

Even now, Abu-Assad manages to find a vein of black comedy in this appalling development. Khaled, having delivered an impassioned final testament on film, is rather put out to learn that the video camera wasn't working and he must go again. Second time round he includes a little message for his mother, dispensing some domestic advice before he departs the planet.

Said, on the other hand, finds his destiny as martyr at odds with both his conscience and his inchoate attraction to Suha, whose education in Europe has inclined her towards pacifist opposition. "Are we doing the right thing?" he asks Khaled, but the mission by now has its own momentum, and the two friends, hair and beards shorn to make them look like "occupiers", are spirited into Israel to carry out their terrible deed.

The emotional twist in the script is to have fanaticism and doubt gradually trade places. Khaled starts out in the certainty of their cause - under the occupation he reckons he's already dead, so blowing himself up holds no fear - while Said, who also has a widowed mother (Hiam Abbass) to think of, hesitates when his opportunity comes round. By the end of the film, however, the ground has shifted, and the unthinkable has become a matter of holding one's nerve.

Paradise Now is passionately argued and played, but one suspects its humanity would be lost on the people it most wants to convince. As Khaled says of the conflict: "If we had airplanes, we wouldn't need martyrs."