Here's the Register's editorial on the death of Aleksandr Solzhenitsyn. According to good Misesian theory the Soviet Union had to collapse eventually because without a price system it couldn't allocate resources intelligently, and by the early '80s I was convinced that its collapse was inevitable whatever the U.S. did or didn't do. Such a theory doesn't predict when such a collapse will happen, however, and doesn't rule out the possibility of events and individuals who might speed up or slow down the process.
I think Solzhenitsyn sped up the process, especially with the publication of "The Gulag Archipelago." (So did Vladimir Bukovsky, whom I met and instantly liked when he spent time at Stanford in the 1980s.) For whatever reason -- maybe it was the Nobel Prize and the literary quality of "Gulag" helped-- in the early 1970s Solzhenitsyn had enormous credibility with western intellectuals, including some who had been more inclined to be critical of anti-communists than communists. Maybe they were just ready to abandon the old dreams of a worker's paradise, or maybe the system was looking creaky. But they paid attention to Solzhenitsyn (it was later, after he took up residence in the U.S. and started criticizing its moral emptiness, etc., that many became disenchanted). And Solzhenitsyn was shrewd; he understood the system from the ground up, and knew just what he could demand, and the Nobel gave him protection from returning to the camps or an arranged death. So they eventually just got rid of him.
Here are a few more remembrances, from the WSJ, from WaPo's Peter Finn and Robert Kaiser, from Chistopher Hitchens, and Serge Schmemann, and Anne Applebaum.