Mikhail Gorbachev major campaign to limit alcohol consumption, which Gorbachev—who believed it would improve health and work efficiency—oversaw. His wife keenly supported the measure. As a result, crime rates fell and life expectancy grew slightly between 1986 and 1987. The reform had significant costs to the Soviet economy, resulting in losses of up to $100 billion between 1985 and 1990. Gorbachev later considered the campaign to have been an error. In April 1986 the Chernobyl disaster occurred; in the immediate aftermath, officials fed Gorbachev incorrect information to downplay the incident. As the scale of the disaster became apparent, 336,000 people were evacuated
Khomeini's letter to Mikhail Gorbachev and Marzieh Hadidchi, went to Moscow to officially deliver the letter. Soviet officials met the Iranian delegation in the airport. Gorbachev then met with the Iranian representatives for approximately two hours, where an interpreter translated the letter for Mikhail Gorbachev and his colleagues. When some part of the letter was unclear, the interpreter asked the Iranian delegation to clarify. Gorbachev listened politely and took notes on its contents. The letter's contents were kept secret, and so Russian officials did not know it was an invitation to consider monotheism and Islam. In his letter, Khomeini congratulated Gorbachev for his bravery in