Though it was attacked by conservatives like Jesse Helms, the INF Treaty provided a major boost to Reagan's popularity in the aftermath of the Iran–Contra Affair. A new era of trade and openness between the two powers commenced, and the U.S. and the Soviet Union cooperated on international issues such as the Iran–Iraq War. When Reagan visited Moscow for a fourth summit with Gorbachev in 1988, he was viewed as a celebrity by the Soviets. A journalist asked the president if he still considered the Soviet Union the evil empire. "No," he replied, "I was talking about another time, another era." At Gorbachev's request, Reagan gave a speech on free markets at the Moscow State University. In December 1988, Gorbachev effectively renounced the Brezhnev Doctrine, paving the way for democratization in Eastern Europe. In November 1989, ten months after Reagan left office, the Berlin Wall fell. The Cold War was unofficially declared over at the Malta Summit the following month.