No, and yes:

Reagan ran up the largest budget deficits to date by increasing defense spending because he and his advisers believed the USSR had gotten a big jump on us in strategic weaponry. Many people believe that his insistence that we build "Star Wars" forced the USSR to follow us, forcing them into economic collapse. The facts that emerged after the USSR broke up are that Soviet economy was in a very precarious state for years due to Brezhnev's senility and the weakness of his two successors. Their spending on conventional and strategic weapons was flat during six of Reagan's eight years in office--and they never spent much on their own "Star Wars" because they believed it wouldn't work. They were ready to topple.

But, yes, Reagan did contribute to the breakup of the Soviet Union by opening a useful and supportive dialog with Gorbachev--in effect, encouraging him in his open and reforming policies within his own country. In so doing, Reagan helped Gorby to pacify the hard-liners by showing them that the US wasn't on the verge of launching a nuclear war, and was open to responding to Gorby's peaceful initiatives. Reagan's willingness to discuss eliminating all strategic missiles showed them that the US could be reasonable. His support was essential for helping Gorby to preside over the dissolution of the USSR. Only a president with Reagan's impeccable anti-Communist credentials could have brought it off, and gotten the American people to support him.