The eleventh of September was a day of great tragedy. But could it also have been the day NATO met its future? Invoking Article 5 for the first time, NATO demonstrated that its members are united and determined to defeat the new security challenges posed by terrorism, the proliferation of weapons of mass destruction and their means of delivery. The individual and collective actions of NATO Allies in response to 11 September came as no surprise to us. Throughout its history, NATO has always been ready to meet new threats and seize new opportunities. That is why the Alliance still matters and why NATO remains the key to the stability and security of the Euro-Atlantic area.

When President George Bush and his counterparts meet in November in Prague, they will mark the profound changes that have taken place in Europe and NATO's central role in making these changes possible. NATO leaders will reaffirm the strength, unity and vitality of the Atlantic Alliance. NATO's fundamentals - shared values, commitment to collective defence and to the importance of the transatlantic link - matter now more than ever. As President Bush said in April, NATO remains "an anchor of security for both Europe and the United States".

On 11 September, we were reminded how dangerous our world still is. The events of that day and the days immediately following also demonstrated how important our Allies are in helping to defeat the new threats that face us. The Alliance derives its strength from our shared purpose in defending our people and our values. NATO is not less important to our security after 11 September. It is more important.

NATO ministers agreed last December to intensify common efforts to meet the threats posed by terrorism, the proliferation of weapons of mass destruction and their means of delivery that all Allies face. And they have followed up with further pledges in meetings in Reykjavik, in Rome, and in Brussels in May and June. When President Bush meets with Allied leaders in Prague, he will join Allies as they approve an action plan aimed at enhancing NATO's ability to deal with new threats. This agenda, which can be summarised as "New capabilities, new members, new relationships", will take the Alliance in new directions even as it reflects the enduring values and common goals set out in its founding charter, the 1949 Washington Treaty - to safeguard the freedom, common heritage and civilisation of our people, live in peace with all peoples and governments, and promote the stability and well-being of the North Atlantic area.

Since the end of the Cold War, the Alliance has taken steps to revise its doctrine and improve its command and force structures to counter what threatens our Alliance today. The 1999 Strategic Concept defined these new threats explicitly, noting that: "New risks to Euro-Atlantic peace and stability were becoming clearer - oppression, ethnic conflict, the proliferation of weapons of mass destruction, and the global spread of weapons technology and terrorism." But we have more to do. The events of 11 September show that the threats to Allies and to our Alliance can come from anywhere, at any time. Now more than ever, NATO needs to be able at short notice to deploy balanced, flexible, well-armed forces capable of conducting sustained operations across a range of military options.

In order to fight effectively alongside the United States, European forces need more capability such as strategic lift, modern precision-strike capability, and combat service support. Unless the disparity is substantially narrowed, our NATO Allies will find it increasingly difficult to play their part in countering the threats that now face us all.

At the Prague Summit, NATO must begin to redress this imbalance by ensuring a comprehensive improvement in European military capabilities. We need to sharpen the focus of the Defence Capabilities Initiative, the high-level programme launched in 1999 to boost Alliance capabilities. Effective European forces can be created by identifying key shortfall areas and agreeing to pool appropriate resources. This is similar to what Allies which are also members of the European Union are doing to meet the so-called "headline goal" of deploying EU-led forces in cases where NATO has decided not to become involved. Other capability requirements can be addressed through country specialisation according to an agreed division of labour. We are confident that these goals can be accomplished. As Secretary for Defense Donald Rumsfeld noted during his 7 June press conference following the NATO defence ministers' meeting: "There isn't a doubt in my mind... that the publics of NATO countries would willingly provide a relatively small fraction of our gross domestic products to provide the kinds of investments that will enable the NATO countries, individually and collectively, to contribute to peace and stability in the world."

NATO also needs the means to defend its forces and members against new kinds of attacks. This means developing effective defence against weapons of mass destruction fielded either by rogue states or terrorist groups or by some sinister combination of the two. With NATO foreign and defence ministers recognising the importance of action to address the capabilities issue, we look forward to a comprehensive package of recommendations for the endorsement of heads of state and government at the Prague Summit.

Our second goal for Prague is to continue the process of building a united Euro-Atlantic community by extending membership to those democratic European countries which have demonstrated their determination and ability to defend the principles of democracy, individual liberty, and the rule of law. The process of enlarging the Alliance to bring in Europe's new democracies, which was launched at NATO's Madrid Summit in 1997, has brought us closer to completing the vision of NATO's founders of a free and united Europe. But here, too, there is more work to be done.

President Bush has affirmed his belief in NATO membership for "all of Europe's democracies that seek it and are ready to share the responsibilities that NATO brings". He has made clear to Allies and aspirants his belief that: "We have acted cautiously; now the time has come to act decisively." We have been working closely with Allies and the nine aspirant countries that have been participating in the Membership Action Plan (MAP) to strengthen their preparations. A team led by US Ambassador to NATO Nicholas Burns visited these nine aspirant countries earlier this year to reinforce the importance of addressing key reform priorities in the months before the Prague Summit. Our team came away from its meetings impressed by the commitment of the aspirants to meeting their MAP goals and advancing reforms, even while recognising that they all have serious work ahead. We have told the aspirants that the United States has made no decision on which countries to support for membership, and we have urged them to accelerate their reforms between now and the Prague Summit.

The Washington Treaty makes clear that states invited to join NATO should be in a position to further the principles of the Treaty and contribute to the security of the Euro-Atlantic area. This is the standard that will be applied as we approach decisions at the Prague Summit. The Vilnius Group of candidate countries, meeting in Sofia, Bulgaria, last October, declared its shared intention to "fully support the war against terrorism" and "act as Allies of the United States". And they have delivered, reinforcing our belief that a larger NATO will be a stronger Alliance.

Some have asked in the aftermath of 11 September whether enlargement should remain a priority. The President's answer is "yes". The events of 11 September have reinforced the importance of closer cooperation and integration between the United States and all the democracies of Europe. If we are to meet new threats to our security, we need to build the broadest and strongest coalition possible of countries that share our values and are able to act effectively with us. The demand is there. In the words of Secretary of State Colin Powell to the Senate Appropriations Committee on 24 April: "Why do we need NATO? Why doesn't it go away? The answer [is] obvious: everybody wants to join the club. It must be doing something right... They want to be part of a political and security organisation that is anchored in its relationship with North America." More than ten years after the fall of the Berlin Wall, countries are still interested in joining NATO - not leaving it. NATO's door must remain open to them.

Our third goal for the Prague Summit is aimed at advancing two other core principles of the Alliance, namely those of living in peace with all peoples and promoting stability in the Euro-Atlantic area. As we work to complete the vision of a united Europe - from which Winston Churchill once observed: "No nation should be permanently outcast" - we must continue to reach out and expand cooperation and integration with all NATO Partners.

NATO and Russia have taken steps to give new impetus and direction to their extensive cooperation in the aftermath of 11 September. President Bush's vision is of a Russia "fully reformed, fully democratic, and closely bound to the rest of Europe", which is able to build partnerships with Europe's great institutions, including NATO. As President Bush observed at the founding meeting of the new NATO-Russia Council in Rome on 28 May: "The NATO-Russia Council offers Russia a path toward forming an alliance with the Alliance. It offers all our nations a way to strengthen our common security, and it offers the world the prospect of a more hopeful century."

The focus of the NATO-Russia Council will be on practical, well-defined projects where NATO and Russia share a common purpose and a common goal. It will change the way NATO and Russia do business, help build trust and understanding, and deepen this key relationship. The new body will not, however, give Russia the ability to veto NATO actions in any area. It is not a back door to NATO membership. It will not infringe on NATO prerogatives. But the new body gives Russia the opportunity to work together with NATO and lay the basis for increased cooperation in the future.

While forging new links with Russia, our cooperative vision for NATO embraces all of NATO's Partners, including countries in the Caucasus and Central Asia, Mediterranean Dialogue Partners and Ukraine. We are particularly determined to focus at the Prague Summit on NATO's Partner activities with the countries of Central Asia that have played such constructive roles in the war against terrorism. The Partnership for Peace and Euro-Atlantic Partnership Council have been successful vehicles for integration, but we believe that much more can be done to expand cooperation between NATO and these countries. Through the Partnership for Peace, NATO can help build reformed, stable, democratic societies in the Caucasus and Central Asia. We need to make sure Partnership for Peace programmes and resources are tailored to their needs, so that they can develop the forces and training they need to meet common threats and strengthen stability.

Fifty-three years after its creation, NATO remains the core of the US commitment to Europe and the bedrock of our security. NATO has kept peace in Europe for more than half a century. NATO continues to provide conventional and nuclear defence for Allies, and it is the nexus of cooperation with the Caucasus, Central Asia, Russia and Ukraine. No other organisation comes close to fulfilling these roles. Together with our Allies, we have much work ahead, but also an historic opportunity to achieve our goals of defending, integrating, and stabilising the Euro-Atlantic area and continuing to strengthen this greatest of alliances. We need no convincing of NATO's importance. We remain committed to its continued success.

The goal of a Europe whole, free and at peace is fast becoming a reality for the first time in Europe's history. As we look back on the emerging consensus of the past months and look forward to NATO's Prague Summit, we see an Alliance confident in its enduring sense of purpose and committed to ensuring that it remains as capable of meeting the new challenges we face as it has those of the past.