Ronald Reagan fell onto an opportunity and took it - his real contribution was actually very limited. Basically any President of the U.S. at that time would have had the same influence.
The real reason it fell was political changes in Eastern Europe and civil unrest in Germany put pressure on the East German government to loosen some of its regulations on travel to West Germany. At a press conference on 9 November, East German spokesman Günter Schabowski announced that East Germans would be free to travel into West Germany, starting immediately. He failed to clarify that some regulations would remain in place.
Western media inaccurately reported that the border had opened and crowds quickly gathered at checkpoints on both sides of the Wall. Passport checks were eventually abandoned and people crossed the border unrestricted. East and West Berliners came together in celebration.
