Lord Robertson of Port Ellen: Nato is equal to the task of a new world

From the Winston Churchill lecture by the Nato secretary general to the English-Speaking Union

To those who sigh wearily that the Cold War is over, and that Nato cannot adapt to today's very different world, I invite them to look at last year's Prague Summit declaration. September 11 2001 gave each of the 19 Nato nations a powerful wake-up call. Wake-up calls are sometimes ignored. Think of Churchill in the 1930s. This one was heeded and it was acted upon. This wake-up call produced the most profound transformation in the alliance's long and distinguished history.

Nato had long since ceased to be a cold war warrior. During the 1990s the alliance intervened to bring peace and security to Bosnia after the bloodiest civil war in recent European history. It acted to end Milosevic's brutal ethnic cleansing in Kosovo. In 2001 it prevented a civil war in Macedonia. It reached out to new democracies in Europe and into the former Soviet Union. It began the process of engagement with Russia, tentative steps but a welcome contrast to the hostility of the Cold War.

September 11 changed the rules completely. But Nato proved equal to the task. Our declaration of article 5 of Nato's Washington Treaty on 12 September 2001, which made the attack on the United States an attack on all 19 Nato countries, turned Churchill's famous dictum on its head. The old world came to the aid of the new.

In parallel, we have turned Nato into the motor for developing military plans and concepts to guide the contribution of armed forces in the war against terrorism and in defending ourselves against weapons of mass destruction. This may sound arcane. But it is 50 years of co-operation of this kind in planning and preparing for conventional military operations which enabled US and European troops to work effectively together in the Gulf War, the Balkans, Afghanistan and Iraq, whether or not Nato was directly involved.

Better still, Nato is not working alone but forms the heart of a much wider set of partnerships, with the EU, Russia, Ukraine and with partner countries from Albania to Uzbekistan. This 46-strong partnership for peace is the world's largest permanent coalition and, thanks to Nato, it is a key player in the fight against terrorism. Churchill, the consummate coalition builder, would have heartily approved.