THE North Atlantic Treaty Organization, widely considered the most successful regional security alliance in history, recently celebrated its 60th anniversary, and it has much to show for it. NATO helped end the Cold War without firing a single shot and is responsible for bringing together a Europe that is whole, free, and at peace - a dramatic achievement considering that two devastating world wars were fought on the continent in three decades.
Despite these past successes, we have lost strategic focus in adapting NATO to meet the challenges of today, and have put off answering some important long-term questions over the last decade. It's essential that we begin the dialogue on NATO's future now because our opportunity to make sure NATO continues to represent a force for good in the world is quickly approaching.
NATO will soon begin a crucial re-writing of its Strategic Concept document, which defines a strategic direction and offers clear guidance for all of NATO's political and military actions. Over the past 10 years, the world has changed dramatically, but the Strategic Concept has not been updated substantively since 1999. In that time we have endured some of the most deadly acts of global terror ever on NATO soil, including the attacks of Sept. 11, 2001, and the bombings in the United Kingdom and Spain. We have made remarkable technological advances that created an interconnected world but bring new security challenges. And we face the potentially devastating dangers associated with the proliferation of nuclear materials and technology around the globe. Our world has changed, and NATO must change with it.
NATO's military commitment in Afghanistan remains the most pressing issue for the Alliance in the short term. But a number of other nontraditional threats face NATO members, including nuclear proliferation, cyber warfare, energy security, piracy, even pandemic health problems. This begs the question: How does NATO find consensus on the scope of its responsibilities, missions, and relationships?
Last week, the Senate Foreign Relations Subcommittee on European Affairs held a hearing on NATO's strategic challenges for the next generation. As policymakers have been busy putting out fires all over the globe, it has been too easy to neglect the kinds of long-term strategic thinking that brought about the creation and ultimate successes of NATO half a century ago and which is desperately needed to meet modern-day threats.
A former senior official at the State Department, Dr. Daniel Hamilton of Johns Hopkins University, spoke of the urgent need to update NATO's mission. He testified that the "security challenges we face have changed, but the need for a common response has not."
Since the end of the Cold War, the debate over NATO's future focused primarily on enlargement and NATO's "open door" policy. The effort has been a great success with the addition of 12 new members since 1999. But despite this important strengthening of the Alliance, we have failed to clearly define what exactly NATO should be doing to address emerging threats.
As we confront these new challenges, we must remember that there are limits to NATO's resources and capabilities. For example, is NATO adequately equipped to meet cyber threats? Or piracy? Or swine flu?
NATO will simply not be able to meet every challenge that threatens its members. On some issues, NATO will take the lead. But on others, NATO will have to partner with other international institutions, like the United Nations or the European Union. As we rewrite the Strategic Concept to guide the next decade of NATO operations, we must clearly define when NATO should lead, when it should collaborate with other international organizations, and when it should take a back seat.
NATO's member nations have some difficult questions to answer. It will not be easy to find consensus on these issues, which is why we need to start this dialogue now. The United States must play a role in shaping this debate so that NATO is as successful for our children as it was for us.
US Senator Jeanne Shaheen chairs the Senate Foreign Relations Subcommittee on European Affairs. 
