In an imagined world all too close to reality, draft-dodging radicals are given a stark choice: go to prison or spend three days in Punishment Park. Peter Watkins' riveting pseudo-documentary reveals the gruelling consequences of option B, as one 'corrective group' begins a 57-mile desert trek to reach a US flag, with a pack of rifle-toting National Guardsmen just a couple of hours behind. Made in 1971 as a response to the social upheavals of the late 60s, the film feels just as shockingly relevant today.

America's involvement in Vietnam looms large in the movie, bringing to mind the debate over more recent conflicts. It's impossible not to see a parallel between Punishment Park and Guantanamo Bay. On top of that, the film evokes the sadistic rituals of reality TV, with Watkins' verite technique having hardly dated at all. Working with a cast of mostly non-professionals (many of whom subscribed to their characters' views), he creates a searing sense of authenticity. But what really resonates is the supple back and forth cuts between the desert ordeal and the trial of seven rebels, implying that the latter's fates have already been set.

"A VIVIDLY EXECUTED PIECE OF PROVOCATION"

By concentrating solely on extreme examples of Left and Right, Watkins ends up presenting a simplified, black and white vision of American life. (It doesn't help that the characters speak in slogans half the time.) But this is still a vividly executed piece of political provocation. As the Punished face 'justice' in the blazing heat, you'll be chilled to the bone.