The 'student movement' of 1968 swept all the way across Europe and the USA. But it had begun the year before in Berlin. The trigger was a demonstration against a visit by the Shah of Persia, and its heavy-handed suppression by the police, during which they shot and killed a student called Benno Ohnesorg. The wave of demonstrations, strikes and sit-ins that ensued all over the world was like the long-stored energy released in an earthquake. It came from a huge idealism that had found little oudet in the cautious compromises of parliamentary democracy. In Germany there were two additional causes of frustration. One was the new generation's realisation that the apparently solid fabric of German society rested upon foundations built out of the rubble of its National Socialist past, and which were by unspoken common consent not to be inspected too closely. The second was the extreme expression of the consensuality of post-war German politics in the Grand Coalition, which left all the functions of an Opposition to the tiny, impotent and far from radical FDP.

So the radical left had constituted itself as an informal 'extra-parliamentary Opposition'. This chaotic grouping was, needless to say, far more disparate than any official coalition could ever be, and it was the spectacular array of its fission products that caught my eye when I arrived in Berlin in 1972. Some of its factions were rigidly subservient to the SED (the 'Socialist Unity Party' that ruled East Germany), some of them were Maoist, some of them nostalgic throwbacks to the KPD, the old Communist Party of the Weimar years, some of them engaged in increasingly brutal terrorism. A wide range of idealistic lifestyles and business enterprises had sprung up in the city, a kaleidoscope of'left-oriented' communes, of pubs and cafés selling drinks and hot cakes at 'comrades' prices'.