His speechwriter at the time, Anthony R. Dolan, has an article about this in the Wall Street Journal of November 8:
Reagan had the carefully arrived at view that criminal regimes were different, that their whole way of looking at the world was inverted, that they saw acts of conciliation as weakness, and that rather than making nice in return they felt an inner compulsion to exploit this perceived weakness by engaging in more acts of aggression. All this confirmed the criminal mind's abiding conviction in its own omniscience and sovereignty, and its right to rule and victimize others.
Accordingly, Reagan spoke formally and repeatedly of deploying against criminal regimes the one weapon they fear more than military or economic sanction: the publicly-spoken truth about their moral absurdity, their ontological weakness. This was the sort of moral confrontation, as countless dissidents and resisters have noted, that makes these regimes conciliatory, precisely because it heartens those whom they fear most—their own oppressed people. Reagan's understanding that rhetorical confrontation causes geopolitical conciliation led in no small part to the wall's collapse 20 years ago today.
Here are Al Mohler's thoughts on the topic.
Ronald Reagan was regularly lampooned as not entirely with it, but he saw some things with great moral clarity.