As Berliners watch 8,000 balloons being released into the night sky this evening, old divisions between east and west will symbolically vanish into thin air with them. Yet the runup to the festivities has already served up plenty of reminders that, 25 years after the fall of the wall that divided the city for three decades, the scars of history are hurting more than ever.Speaking at a symposium near the Brandenburg Gate yesterday morning, former Soviet president Mikhail Gorbachev warned that the world was “on the brink of a new cold war” and strongly criticised the west for having sown the seeds of the current crisis by mishandling the fallout from the collapse of the iron curtain.“Instead of building new mechanisms and institutions of European security and pursuing a major demilitarisation of European politics … the west, and particularly the United States, declared victory in the cold war,” said the man behind the Soviet Union’s glasnost and perestroika reforms.“Euphoria and triumphalism went to the heads of western leaders. Taking advantage of Russia’s weakening and the lack of a counterweight, they claimed monopoly leadership and domination in the world.”The centrepiece of the festivities will be formed by an ambitious art installation. Since Friday morning, 8,000 white balloons have been pegged to the ground along the former border. After sunset, they light up to form a 15km-long “wall of light”. This evening the balloons will be released int.