Lebanon, Samuel Maoz, 93 mins (15)

With the current 3D boom, the latest hot word in cinema is "immersive".

Israeli war film Lebanon is an immersive experience all right, but while Avatar suits a giant screen, this autobiographical feature by Samuel Maoz is best watched in a cramped cinema with leaky pipes and bad ventilation. Then you'll get the full effect of this brutally claustrophobic drama set inside a tank during the 1982 Israeli campaign in Lebanon.

The main characters are a young four-man Israeli tank crew, out of their depth and prone to panic; occasionally, an older officer turns up to put the fear of God into them. Trouble starts when gunner Shmulik (Yoav Donat) has an attack of nerves when ordered to fire, and an Israeli soldier is killed. When Shmulik does shoot, it's at civilians, leaving a man dying with his limbs blown off. That sight is even more shattering because, like everything outside, it is seen through the tank's viewfinder.

This formally brilliant, unnerving film keeps us cooped up with its main characters, making the action at once tense and somewhat theatrical. Meanwhile, the horror and chaos outside are framed through the viewfinder that Shmulik peers through – a circle marked with target crosshairs, which gets progressively harder to see through as the lens is obscured by cracks and dirt. This restricted view concretely mirrors the confusion of the squad, who are ordered to plough on regardless, however little they understand of what's happening. The already limited space gets more crowded, the crew joined by a dead body, a Syrian prisoner and a menacing Phalangist. And, as the tank takes a shelling, its bowels gradually fill with water, oil, fag ends and soup croutons. Seeing this film is like being trapped inside a dirty tin box that's being violently rattled.

Emerging from the same traumatic experience as Avi Folman's Waltz with Bashir, Lebanon was also a therapeutic undertaking for its director. Some critics object that the film is about the Israelis' ordeal, rather than that of the Lebanese, but that misses the point. Maoz recalls his experience, rather than presume to speak for others. But one grim sequence has a woman, caught in the shelling, staring directly into the tank's viewfinder with wordless accusation, and that makes it quite clear how Maoz feels about his involvement. Lebanon is an audacious evocation of the sheer, wretched confusion of conflict. The fog of war rarely seemed more stifling.