But in the darkest hours, the people of Berlin kept the flame of hope burning. The people of Berlin refused to give up. And on one fall day, hundreds of thousands of Berliners came here, to the Tiergarten, and heard the city's mayor implore the world not to give up on freedom. "There is only one possibility," he said. "For us to stand together united until this battle is won … The people of Berlin have spoken. We have done our duty, and we will keep on doing our duty. People of the world: now do your duty … People of the world, look at Berlin!"
People of the world -- look at Berlin!
Look at Berlin, where Germans and Americans learned to work together and trust each other less than three years after facing each other on the field of battle.
Look at Berlin, where the determination of a people met the generosity of the Marshall Plan and created a German miracle; where a victory over tyranny gave rise to NATO, the greatest alliance ever formed to defend our common security.
Look at Berlin, where the bullet holes in the buildings and the somber stones and pillars near the Brandenburg Gate insist that we never forget our common humanity.
People of the world – look at Berlin, where a wall came down, a continent came together, and history proved that there is no challenge too great for a world that stands as one.
Sixty years after the airlift, we are called upon again. History has led us to a new crossroad, with new promise and new peril. When you, the German people, tore down that wall -- a wall that divided East and West; freedom and tyranny; fear and hope -- walls came tumbling down around the world.
From Kiev to Cape Town, prison camps were closed, and the doors of democracy were opened. Markets opened too, and the spread of information and technology reduced barriers to opportunity and prosperity. While the 20th century taught us that we share a common destiny, the 21st has revealed a world more intertwined than at any time in human history.
The fall of the Berlin Wall brought new hope. But that very closeness has given rise to new dangers – dangers that cannot be contained within the borders of a country or by the distance of an ocean.
The terrorists of September 11th plotted in Hamburg and trained in Kandahar and Karachi before killing thousands from all over the globe on American soil.
As we speak, cars in Boston and factories in Beijing are melting the ice caps in the Arctic, shrinking coastlines in the Atlantic, and bringing drought to farms from Kansas to Kenya.
Poorly secured nuclear material in the former Soviet Union, or secrets from a scientist in Pakistan could help build a bomb that detonates in Paris. The poppies in Afghanistan become the heroin in Berlin. The poverty and violence in Somalia breeds the terror of tomorrow. The genocide in Darfur shames the conscience of us all.
In this new world, such dangerous currents have swept along faster than our efforts to contain them. That is why we cannot afford to be divided. No one nation, no matter how large or powerful, can defeat such challenges alone. None of us can deny these threats, or escape responsibility in meeting them. Yet, in the absence of Soviet tanks and a terrible wall, it has become easy to forget this truth. And if we're honest with each other, we know that sometimes, on both sides of the Atlantic, we have drifted apart, and forgotten our shared destiny.