The Atlantic Alliance is one of the longest-lasting alliances in history. For 40 years this transatlantic organisation weathered the rough waters of Europe's Cold War division. After the East-West conflict had come to an end, it set out to build a new security architecture for an undivided Europe. The continent-wide network of partnership and co-operation, the accession of new members, the new relationship with Russia and Ukraine, and not least NATO's key role in the Balkans, all testify to NATO's unique ability to shape the strategic environment. Today, as we celebrate our fiftieth anniversary, we can proudly say that the signing of the Washington Treaty in 1949 by far-sighted European and North American statesmen ranks among the finest hours of our history. The reasons for NATO's success are manifold. But fundamentally they lie in the fact that NATO is not an alliance in the traditional sense. Unlike past alliances, which came together as temporary coalitions of convenience, NATO is permanent. Although the Washington Treaty was initially conceived as a short-term measure to inject self-confidence into a weak and fragmented post-war Europe, the notion of creating a lasting bond between North America and Europe was clearly present at the creation of the Alliance. Since then, the transatlantic relations cemented in NATO have grown in depth and intensity. Today, they have led to a true transatlantic community of values and interests that extends into political, economic, social and cultural areas. THE NEW SECURITY AGENDA NATO's fiftieth anniversary gives us every reason to be proud of our achievements. Yet pride must not be mistaken for complacency. The project of managing security is far from over. The end of the twentieth century still leaves us with much unfinished business: Europe's integration must widen and deepen; long-term peace must be established in the Balkans, Russia must settle herself within the new emerging structures; a new, more mature transatlantic relationship must be built. Without the successful accomplishment of these tasks, the challenges of the approaching twenty-first century would quickly overtax our ability to manage. And, as it is becoming increasingly clear, there will be no shortage of challenges that can affect the peace and stability of the Euro-Atlantic region.