What step did soviet leader mikhail gorbachev take in reaction to president reagan's 1983 strategic defense initiative?

Disarmament talks--Gorbachev knew the USSR could not economically survive another arms race. 

SDI (Star Wars) convinced Gorbachev that the USSR could not financially endure a revamp of the arms race. He answered the program with negotiations in Geneva and Reykjavik in an attempt to create disarmament treaties with the US. He hoped for agreement to rid the countries of nuclear weapons.