1968 is an over-written year if ever there were one, and the refrain usually goes "Crazy students, sex, drugs and rock'n'roll". In contrast, Tariq Ali and Susan Watkins's month-by-month account takes a refreshing look at 1968 - from the Tet offensive to women's liberation; from the Paris uprising to the tanks entering Czechoslovakia. Among the familiar events are many which are less known, such as the trial in the Soviet Union of four young intellectuals who had defied censorship and campaigned for peace.

The international span makes this an impressive record. Mexico, Brazil, Pakistan and the Palestinians are there as well as the US and Europe. Marching in the Streets shows, too, how 1968 radicalised culture. Censorship was at issue in Poland and Pakistan. In Italy, the students invited the veteran psychoanalyst Musatti to talk to them. The Rolling Stones sent their song "Street Fighting Man" to Black Dwarf, a left paper that I worked on with Tariq Ali.

There are amusing bits: for instance, a dozen taxis full of American sailors heading to a brothel are surrounded by Japanese students protesting against their country's use as a US military base; and Eartha Kitt challenges a nonplussed Lady Bird Johnson on Vietnam at a ladies' lunch.

However, seeing 1968 in international terms makes for a more sobering account than the stereotypes. Protesting students were seriously wounded, and some died, while others were imprisoned. The rebels were so young: Abdul Hamid of Pakistan was 17 when he was shot; so was the Vietnamese girl in black pantaloons executed after a guerrilla attack on the presidential palace in Saigon. They seem like children to me now. At the time, I felt a veteran at 25.

Marching in the Streets records how modest many of the demands were. Students protested against poor living conditions, against war and censorship and for democracy - yet the reaction was frequently violent. These were idealistic revolutionaries. Seriously wounded, the German student Rudi Dutschke wrote to his would-be assassin trying to explain his politics.

The authors say it is simply a chronicle. But chronicles are rarely written with such deft dramatic irony, nor are they usually so ebullient or scattered with jokes. Moreover, Tariq Ali and Susan Watkins have done something which is a challenge to any historian: they have made utopian rebellion intelligible.

Jean-Paul Sartre told the perky anarchist Daniel Cohn-Bendit: "Something has emerged from you which surprises, which astonishes and which denies everything which has made society what it is today. That is what I would call the extension of the field of possibility. Do not give up." Many did not give up despite (or because of) all the sex, drugs and rock'n'roll. Those Utopian ideas - that knowledge should be accessible, work democratised and time claimed for living and loving, not just for making money - are even more relevant 30 years on. This is a Molotov cocktail of a book, to make the Blairites blanch.