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The German people, and the whole world alongside them, are today celebrating a landmark date in history: the 20th anniversary of the fall of the Berlin Wall.

Not many events can claim their place in the collective memory as a watershed that divides two distinct periods. The dismantling of the Berlin Wall — that stark, concrete symbol of a world divided into hostile camps — is such an event. It brought incredible hope and opportunity to people everywhere, and provided the 1980s with a truly jubilant finale. That is something to think about as this decade draws to a close, and the chance for humanity to take another momentous leap forward appears to be slipping away.