The early Seventies were the age of the urban guerrilla. The news was full of plane hijackings and car bombs, industrialists and heiresses being kidnapped and – to me, as a child – thoroughly confusing connections being made between Germany, Cuba and the West Bank. The terrorists looked like hippies or – in the case of the Red Army Faction – West Germany’s World Cup-winning team. They certainly looked less like the bad guys than Richard Nixon did.

The fortieth anniversary of the 1968 événements has thrown up parallels between Iraq and Vietnam, raised endless discussion about lost ideals and pipe dreams, caused much brow-furrowing. Yet the violent underground aftermath that turned words into direct action has barely been mentioned. The urban guerrilla groups were visceral, suicidally naive, born out of the belief that the State was so oppressive that things couldn’t get worse. The Barbican’s History is Now! season, which begins next week, will centre on two contemporaneous and two recent documentaries covering groups in Britain, Germany and America; all four are sharply nonjudgmental.

While the groups may not have claimed a direct link to 1968 it’s hard to imagine that any of them weren’t stimulated by the uprisings in Paris, Chicago, London and Berlin. According to all four films the organisations formed in response to state control and American foreign policy. Russ Little of the Symbionese Liberation Army (SLA) says he “grew up with Zorro and Robin Hood, all these tales of people who were fighting against the government”.

In Guerrilla: the Taking of Patty Hearst (2004), the story of the SLA and the kidnap of the heiress Patty Hearst in 1974, the authorities are one step away from blind panic – why has no one ever heard of the SLA? What kind of “army” is it? The police guessed that the SLA – whose membership barely reached double figures – was “growing day by day”. The bloody intervention that followed was as calamitous as the Waco tragedy two decades later.

No question, the SLA story lends itself well to cinema. Hearst’s transformation from victim to urban guerrilla, mocking her father (“He could have done better”) as he acquiesced to SLA demands by feeding the poor of San Francisco’s Bay Area, was deemed by her defence to be the result of brainwashing by her captors. Others claimed it was a case of Stockholm Syndrome, the term coined in 1973 after a Swedish bank siege in which the employees ended up sympathising with the robbers. Either way, Hearst was the only SLA member not dead or behind bars when Guerrilla was released.

I remember no public outrage against these groups at the time, just numb voyeurism. In the part-drama, part-documentary Germany in Autumn (1978), Rainer Fassbinder's mother says “it reminds me of the Nazi era; people stayed quiet to avoid trouble”. Both Germany in Autumn and The Angry Brigade (1973) recall the sense of cold crisis that permeated the Seventies.

However you viewed their politics or actions, the urban guerrillas made a sort of sense: the barely concealed police murder of a Black Power leader in his sleep stirred the Weather Underground; the deaths of four students at Kent State University and, most of all, the re-election of Richard Nixon’s corrupt regime gave the SLA cause to take up arms. “Death to the fascist insect that preys on the life of the people,” was the SLA’s clunky slogan. Now the word “fascist” is associated with bigotry.

These films make you realise how close 1968 and the urban guerrilla aftermath were to the Second World War. In the minds of Baader-Meinhof, the State had allowed fascism to happen, so how could it be trusted? As a former SLA member, Mike Bortin, says: “We saved the world from Hitler. Then you turn around and we’re being Hitler.”

The History Is Now! season begins at the Barbican, EC2 (020-7638 8891) on May 6 2008. Details www.1968.org.uk

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