WITH THE BREAKUP of the Soviet Union in 1991, the Cold War ended. The media not only watched, but played a crucial role in the years after 1985, when Mikhail Gorbachev came to power, as rapid developments dramatically changed the world as we had known it. Images of seminal change agents in what had been the Eastern bloc-Gorbachav, Lech Walesa, Vadav Havel-facing leaders from the West-Ronald Reagan, Margaret Thatcher, Helmut Kohl and Pope John Paul II-mingled with those of explosions at Chernobyl and Tiananmen Square, the of the Berlin Wall and the Bucharest crowds who brought down a Romanian tyrant. Reagan met with Moscow dissidents. Gorbachev prased the flesh on the streets of New York. In Moscow, an attempt~ coup by old-style Soviet hard-liners failed in large part because of conununication technology-Yeltsin could reach the rest of the world by fax, and CNN showed everyone (Gorbachev, Yeltsin, Bush and the putschists alike) what was happening at the barricades. A new world.