ACIN:

Nixon's effort to "open" China was a brilliant move, but the break in Sino-Soviet relations went back to Kruschev. Kruschev's split with Mao was almost certainly a product of his need to distance himself from Daughasvili (sp?), with whom Mao had worked well. None of these events occur in isolation.

Reagan's efforts did indeed increase pressure on the USSR, mostly as a result of Russian paranoia -- "collective security," what a pipe-dream doctrine -- but the flaws in the Soviet system went back decades and Reagan was certainly not the only U.S. President trying to use that to win the Cold War. I suspect that both leaders at Rekjavik had more of an impact than anything else.

Reagan's handling of the Middle East was also far too "short-term" in its outlook. Actions that seemed just at the time have had ramifications decades later.