The measure of any organisation is not how it performs when everything is going well, but how it responds when the going gets rough. In this respect, the Alliance has in the months since November's Prague Summit had to confront issues where member states have disagreed and where it has taken difficult negotiations to reconcile the various national positions.

The beginning of 2003 saw intense debate among Allies on the timing of defensive support for Turkey to deter possible attack by Iraq. But difficult, consensus-building negotiations are the essence of NATO. Moreover, in spite of differences over policy towards Iraq, within Europe and across the Atlantic, despite mass protests and impending elections in several NATO countries, the Alliance achieved sufficient consensus to provide Turkey with defensive assistance to meet the threat posed by Iraq.

Again, the issue was timing, not substance. In spite of their differences, Allies demonstrated that they take their treaty obligations seriously and are ready to meet them. Although a quicker and quieter resolution would have been preferable, the end result is what counts. Moreover, planning was followed by a rapid decision to deploy assets to Turkey.

In the coming months and years, Alliance members will again no doubt have to work hard to build consensus when faced with difficult issues. Indeed, even during the Cold War, NATO countries often disagreed with each other. As former Secretary General Lord Carrington was fond of saying, unlike the Soviet bloc, NATO sang in harmony, not in unison. It is because of the Alliance's democratic diversity that NATO works in good times and bad and that, in the period since 9/11, it has already achieved broad consensus in a number of crucial areas.

First of all, we have reached agreement on the character of the new threats and on the best way that NATO and its members should respond to them. Terrorism and the proliferation of weapons of mass destruction are two of the defining challenges of the 21st century. The NATO Allies acknowledged this by invoking Article 5 in response to the 9/11 attacks. And they did so again by sending forces to Afghanistan to fight al Qaida and the Taliban. As a result, in 2002, we effectively buried the perennial debate on whether NATO could or should go "out-of-area".

At the Prague Summit, we took that consensus a decisive step further. We agreed a new military concept for defence against terrorism, which states that our forces must be able to "deter, disrupt and defend" against terrorists, and that they should do so wherever our interests demand it. Moreover, the Alliance has already substantiated that commitment by providing support for the Dutch-German command of the International Security Assistance Force that is now deployed in Kabul.

We have also come a long way towards building a new consensus on how to handle the threat posed by weapons of mass destruction. In Prague, NATO leaders agreed to improve detection capabilities, to equip NATO forces with better protective gear, and to support civilian authorities in case of an emergency. And they launched a new NATO Missile Defence feasibility study to examine options for protecting Alliance territory, forces and population centres against the full range of missile threats.

A new consensus has also emerged on the military capabilities that we need to deal with the new threats. In Prague, agreement was reached on reforming NATO's command structure to make it more responsive and more rapidly deployable. The Allies also committed themselves to major improvements in key areas of modern operations: strategic transport, interoperability, and precision-guided munitions, among others. Many Allies committed to making improvements individually, others to forming teams to address shortfalls more effectively. But importantly, all these commitments are clear and specific — which will make it easy to monitor progress. In this way, the Prague Capabilities Commitment marks a real turning point in the adaptation of European capabilities to the requirements of the 21st century.

Another major breakthrough in the capability area was the agreement reached in Prague on the creation of a NATO Response Force (NRF). This state-of-the-art force will give the Alliance the capacity to respond quickly and effectively to new threats. The NRF will balance risks more fairly by engaging more Allies in actual operations, rather than in post-conflict responsibilities alone, simply by default. And by bringing together the best forces from both sides of the Atlantic, the NRF will also serve as a catalyst for the necessary transformation of all Allied forces. Once again, a remarkable new consensus was achieved in an extremely short time.

Before 9/11, the Prague Summit was generally expected to be focused on NATO enlargement. In the event, the issuing of invitations to seven new countries became part of a much broader transformation agenda. But there is strong consensus that the Alliance's enlargement remains a strategic imperative, even after the seven invitees formally accede next year. This is because, together with the expansion of the European Union, NATO's enlargement will help consolidate Europe as a common security space. And this will be a great step towards turning Europe into a continent from which wars no longer originate.

Some security analysts have questioned whether NATO will be able to operate with many more members. To be sure, more views will be expressed around a larger North Atlantic Council table. But, as we have seen with earlier rounds of NATO enlargement, more views do not necessarily mean more different views. While none of the seven invitees possesses spectacular military capabilities, each of them has niche capabilities that will be valuable to NATO. Moreover, they will bring enthusiasm, a willingness, if necessary, to take on risks, and an appreciation of the value of a permanent transatlantic Alliance. Based on such strong political commitment, NATO will remain a vibrant organisation, regardless of how many members it has.

9/11 transformed terrorism from a domestic security concern into a truly international security challenge. For this reason, the Allies have been keen to involve their 27 Partner countries in meeting this threat. The Partnership Action Plan on Terrorism agreed in Prague identifies opportunities for concrete cooperation in this area. Broader efforts to assist Partners with domestic reform and security issues should have a positive effect on the root causes of terrorism, and its spillover into other countries.

Cooperation with one particular Partner, Russia, has already received a major push over the past year. In the wake of 9/11, the NATO Allies and Russia rapidly realised that they face common dangers and can no longer afford to argue over issues such as NATO enlargement. This realisation led to the creation, in May of last year, of the NATO-Russia Council. Moreover, it continues to encourage constructive cooperation under the aegis of that forum on a wide range of security issues, including combating terrorism and preventing the proliferation of weapons of mass destruction.

Just after the Prague Summit, in December of last year, we achieved another breakthrough by agreeing a formal basis for cooperation between the Alliance and the European Union in crisis management and conflict prevention. Before then, although the two organisations were able to cooperate successfully in the field, notably in heading off civil war in the former Yugoslav Republic of Macedonia* in 2001, we were unable to institutionalise the relationship. This has now changed.

The new EU-NATO agreement holds the potential of transforming not only European security, but also the transatlantic relationship. By enabling EU-led operations to draw on NATO assets and capabilities, both sides of the Atlantic stand to gain. The European Union will have the opportunity to demonstrate its potential as a serious security actor. And if it is gradually able to take greater responsibility for stability in the Balkans from NATO, US forces, in particular, will become available for other pressing tasks. This will help facilitate a new, fairer burden-sharing between the United States and a more mature Europe.

All in all, we have come a remarkably long way since 9/11. There has been a broad convergence of views on the new threats that we face and how best to respond to them; on the capabilities that we require to respond; on the contribution that new members will be able to make to our cause; and on the need to work with Partner countries and our key strategic partner, the European Union. It is clear, at the same time, that we cannot be complacent.

First of all, NATO and its members have a demanding agenda ahead in meeting the various commitments that were made at the Prague Summit. This applies to enhanced efforts to meet the terrorist threat, including deeper cooperation with our Partners. And it applies, in particular, to the commitments that each of NATO's 19 members has made under the Prague Capabilities Commitment, each and every one of which is fundamental to NATO's longer-term effectiveness and credibility.

Second, we must complete our links with the European Union. Work on implementing the December agreement started immediately, with particular emphasis on allowing the European Union to take over NATO's mission in the former Yugoslav Republic of Macedonia.* But the longer-term potential for our cooperation stretches well beyond crisis management in the Balkans. And it is bound to become even greater as both organisations enlarge and have as many as 19 members in common.

Third, we need to redouble efforts to bring the wider public along. One of the characteristics of this new security environment is that our security policies — and our institutions — are changing faster than the perceptions of our publics. As a result, the task of explaining what NATO is and what it is doing is becoming ever more demanding. We must therefore exercise additional effort to ensure that public understanding of the new NATO remains widespread, strong and supportive.

9/11 and Iraq demonstrate that we are in a period of fundamental transition. The security environment is changing, as is the way in which we react to it, and to each other. What is crucial during such a period of transition is that we preserve and strengthen what has brought us where we are today, and delivered so much for our security, prosperity and well being. That is, in a nutshell, our common transatlantic culture of trust, cooperation and mutual support.