1.The Warsaw pact was dissolved
2. The Baltic states declared independence
3. Gorbachev was overthrown by Yeltsin (who was anti communist)
4. Gorbachev was restored but he had lost authoriy so he stepped down and the Soviet Union split into several different states
also the reuniting of Germany showed that communism was falling
you could talk about the reagan doctrine put forward by Ronald Reagan. This basically said that he was going to increase nuclear weapons and put them into space (he called this star wars, or strategic defence initiative). This then forced Russia to obviously catch up with this, but economically, they couldn't. This means that they lost the arms race and alongside other factors, meant that they collapsed. Many historians have said that this would have never have happened (we never found out because the cold war ended before they had time to deploy weapons to space) and that it was just American propaganda towards the Soviets to make the Kremlin panic.