When the Berlin Wall fell on 9 November 1989, the abrupt opening of what had for decades been a hermetically sealed border left the people of East Berlin to stream through their suddenly united city, disbelieving and intoxicated with joy. The events of that day were greeted with especially palpable enthusiasm and support across the Atlantic – in the United States. German reunification, a masterpiece of diplomacy on the part of the government of Helmut Kohl and Hans‑Dietrich Genscher, could not have come about as it did without the close and trusting support of the US administration. But it was not only in the halls of government that Americans felt solidarity with Germans and shared their joy: the millions who had spent time in Germany as GIs or members of military families, or who simply rejoiced in the triumph of freedom, joined in as well – understanding this freedom to be theirs too.

On 11 September 2001, when al-Qaida terrorists hijacked airplanes to carry out the worst terrorist attack in history in New York, Washington DC and Pennsylvania, we were left not only with the horror of the indelible images that have lingered in all of us, but also with a great outpouring of compassion, empathy and solidarity in Germany. We felt compassion for and closeness to the American people, especially the so terribly afflicted people of New York. From the demonstration of solidarity at the Brandenburg Gate, which I personally recall so well, to the countless small signs of German-American friendship, what was expressed in these days was a bond that had grown through decades of close alliance. For the first time in its history, NATO invoked the mutual defence clause. Since autumn 2001, German soldiers have been standing side-by-side with Americans and other ISAF partners in Afghanistan, where the murderous attacks originated.

9/11 changed the world. The allies have not always agreed on the decisions made in the years since. But being part of an alliance means being able to depend on the others in your hour of need.

We have now been in Afghanistan for ten years. So that we do not remain for another ten, the time has come to return responsibility for the security of their country to the Afghan people, step by step, province by province. Our alliance is pursuing a shared strategy which includes not only the handover of responsibility for security by 2014 but also support for internal reconciliation in Afghanistan, so that the country can finally achieve lasting peace and never again become a haven for terrorists. It remains our goal for the engagement of Bundeswehr combat troops in Afghanistan to end in 2014.

The vulnerability of our interconnected modern world makes it necessary for us to continually weigh the balance between freedom and security. In part through the wise case law of the Federal Constitutional Court, we have learned how important it is for the balance not to tip too far to either side. This year’s Arab Spring has emphatically – and unexpectedly – reminded us of the unfailing attraction exerted by the concepts of freedom and the right of every individual to develop freely. The events unfolding south of the Mediterranean should embolden us to stand by our shared values and ideals even in the face of challenges, and not to falter in our convictions. The move forward into a freer society by the people of North Africa shows us that encounters between different religions and ways of life by no means have to prompt a clash of civilizations.

Ten years after 11 September, we are living in a changing world. As the old order begins to waver, the contours of a new order are only just becoming discernable. New centres of power have emerged, countries and societies whose claim on a role in shaping global politics derives from their economic dynamism. New global problems have come to the fore, demanding new globally generated solutions. Even Europe and the USA together can no longer conceive and negotiate these solutions without the input of others. We need new partnerships in order to progress in the difficult pursuit of consensus for global decisions in the United Nations, the G20 and other bodies.

Developing a cooperative world order is the formative task of our times. We will not achieve this overnight. But if we as Germans want to play a part in shaping it, we can only hope to do so through the shared efforts of a unified Europe and a close partnership with the USA. This is not a matter of gratitude or traditional ties. It is a matter of shared beliefs and shared goals, a community of shared values and interests. Despite all our differences we are united by the ideal of an open society and the unfettered development of the individual. This notion has found its unparalleled expression in the American Constitution in the phrase “the pursuit of happiness”. This ideal, too, was one of the targets in the crosshairs of the 9/11 terrorists. Today it remains more alive than ever before. This fact gives us cause for joy and optimism, and should spur on the transatlantic partnership in shaping the future together.