In reflecting on the events which led up to the wall coming down, it seems there were a few key events which almost didn't happen.
- German Politburo member Günter Schabowski accidently blurted out at a press conference that East Germany would allow its citizens to pass through border crossings into the West, and then made it worse by adding that this would happen immediately, even though that was not what East Germany was actually planning to do. Because of that error, people gathered at the borders and at the wall on Nov 9, 1989. More about this here.
- According to this video, Ronald Reagen almost didn't say his famous words: "Mr. Gorbechev, tear down this wall!"
- Margaret Thatcher was actually not supportive of German re-unification, fearing that a unified Germany would be too powerful a force in the center of Europe.
Here is a list of walls which are still standing around the world.