In Europe

built. Most of them were finally forced to move. This allowed the DDR authorities to create a bare strip of land several hundred metres wide between the
Hinterlandmauer
, the actual barrier for the East Germans, and the wall itself. On the other side of that, in turn, lay a closely monitored border zone 2.5 kilometres wide.
    Meanwhile, however, the S-Bahn remained the official property of the DDR until 1984, and during all those years the personnel trains shuttled blithely back and forth between East and West. Three West Berlin lines of the U-Bahn ran, in turn, beneath East Berlin, past fifteen bricked-up ghost stations. For years, telephone calls between the two parts of the city had to be routed by way of Sweden, or via the internal lines of the S-and UBahns. Mourning became a subject of deep mistrust: a special ‘grave card’ was needed to visit the Invalidenfriedhof and the Sophien-Friedhof, the two cemeteries along the border. At the same time, however, Werner Fricke, an employee of the East German Potsdammer water company, calmly walked past the guard posts each day, to tend to the pipes and valves that happened to lie on the western side of the wall.
    Only once had I seen the wall from the wrong side. It was during a student-exchange visit, and our DDR guide invited us to come and take a look. We climbed onto a platform and suddenly found ourselves standing eye to eye with all those Westerners on the platform on the other side. We stared at each other and saw ourselves, it was insane.
    Of the 19 million East Germans, 2.5 million left for the West, the great majority of them in the 1950s. Approximately a thousand people were killed while attempting to escape the country, most of them along the Berlin Wall. One particularly spectacular and successful escape was organised by
Reichsbahn
engineer Harry Deterling, who rammed his locomotive number 78079 (and a few carriages full of family members in the know) past the stunned border guards and into the West. The conductor, an East German policeman and five unwitting passengers walked back to the East in a huff, along the rails.
    Very unusually, the East German songwriter Wolf Biermann – later‘
ausgebürgert
’ – was allowed to give a concert in the West in 1965. For the occasion, he wrote ‘A Winter's Fairy Tale’:
    In German December then flows the Spree
From East to West Berlin,
And there I swam with the railroad,
High over the wall again,
I threaded my way across a wire of steel,
High over the bloodhounds again …
    The barrier over which crowds climbed in 1989 was the fourth-generation wall. Seized DDR documents showed that the technical staff of the border police were by then already working on plans for a fifth generation. This High-Tech-Mauer-2000 would be able to resist all attempts at escape, without a shot being fired. In the DDR policy paper, dated 8 May, 1988 and entitled
Zur Entwicklung von Grenzsicherungstechnik für
1990 — 2000
, the policymakers enthused about ‘micro-electronic sensor technology’, ‘microwave modules’ and ‘seismic alarm systems’ designed to detect intruders immediately. There was only one problem: the sensors could not distinguish between people and stray dogs. Such documents are clear proof that the wall, in one form or another, was intended to outlive us all.
    On 26 May, 1987, nineteen-year-old amateur pilot Mathias Rust landed his little Cessna in Red Square, right in front of the Kremlin. Taking off from Helsinki and flying just above the trees, he had passed the Soviet lines of defence unchallenged. It was meant as a joke, but the Soviet leaders were thoroughly shocked. This was impossible, but it had happened anyway.
    Looking back on it, Rust's escapade was historic. His landing in Red Square was an unignorable symbol, the writing on the wall, a sign that the all-powerful Soviet Union was no longer fully in control. At the time, however, no one recognised its significance.
    Starting in the mid-1970s, Western intelligence services had begun to wonder about the Soviet Union's defence spending, especially after a political refugee reported that the Soviets were spending as much astwelve per cent of their gross national product on defence, double what the CIA had thought. One of the agency's Soviet experts, William Lee, then calculated that the actual figure was probably twice that, around twenty-five per cent. The only possible conclusion was that the Soviet economy was on the verge of collapse. His bosses,