Perestroika
Perestroika, which means "restructuring" in the Russian language, was a series of changes to the structure of the Soviet economy. Soviet leader Mikhail Gorbachev started the policy in 1986. This happened only a few years before the Soviet Union dissolved into 15 new countries. Many historians argue that it was a major reason that the Soviet Union fell apart. Perestroika was introduced around the same time as Gorbachev's "glasnost" reforms, which loosened restrictions on the media and allowed for criticism of the government. It was the first time such changes were implemented in the Soviet Union, and uncovered a lot of secrets about how the Soviet system operated. It also uncovered events which the public were unaware of, such as Chernobyl occurring three days before any announcement was put out, or the deals that Stalin made with Hitler during WWII.