You have to wonder whether the leaders from the NATO countries, who will be convening Wednesday through Friday in Bucharest, will not feel just a touch of nostalgia for the old days of the Cold War when the world seemed so much simpler. They will in fact be meeting in the cavernous halls of the humongous Romanian parliament building, built by Romania's crazy communist dictator Nicolau Ceausescu. All the charms of the Stalinist esthetic are on full display in these halls, where human beings are dwarfed by the sheer scale of the building, which stands as a reminder of a very different era.

Of course, the truth is that the world back then, when the two military alliances were in a frozen stand-off, was not a better place, far from it. Any moment, the conflict could have gone from cold to hot, with devastating, potentially apocalyptic consequences for the world. It is the case, though, that the military purpose of the NATO alliance in Europe was far easier to grasp back then. NATO's first Secretary General Lord Ismay used to say somewhat brusquely that it was to keep the Soviets out, the Americans in, and the Germans down.

Most of the countries that formerly formed the competing Warsaw Pact are now NATO members and even Russia, the core of the former Soviet Union and Warsaw Pact, has a formal relationship with NATO through the Russia-NATO council. The engagements that NATO has undertaken since the end of the Cold War, the operation against Serbia in 1999, and the ongoing war in Afghanistan, bear no resemblance to the task of defending the heartland of Europe from invasion from the East, which NATO was designed for.

The numerous calls today for a new strategic concept for NATO are an indication of the current predicament of the alliance. Ever since the collapse of the Soviet Union, NATO has been an alliance in search of a purpose, and judging by discussions leading up to the summit, it still is. To recap a few of the issues that will be discussed. It is likely that all of these items will be hotly debated, as the alliance seems less and less able to reach consensus.

• A further round of enlargement, with Balkan states, Albania, Croatia and Macedonia being next in line is on the table. Of these:
  
• Membership action plans for former Soviet states Georgia and Ukraine, which have been proposed by the Americans and opposed by Europeans as always fearful of antagonizing Russia.
  
• Re-entry of France into the NATO military command structure, contingent on American blessing of a separate European defense force.
  
• Improved cooperation in Afghanistan, where some NATO members place ridiculous constraints on their forces, such as avoiding areas of actual fighting, and staying on base at night.
  

In the search for a new strategic concept, some have proposed that NATO become a global organization - indeed if it continues to expand, it may well indeed become one. As we look at global threats like terrorism and proliferation, this line of thinking is fruitful. As a global power with important allies not just in Europe but Asia as well, the United States could draw into an alliance relationship its friends that are currently more loosely connected - or not connected at all, such as Australia.

In "Liberty's Best Hope: American Leadership for the 21st Century," Kim Holmes, Heritage Foundation vice president for foreign and defense policy, proposes moving beyond the Cold War paradigm and looking at a Global Freedom Alliance, who membership would be composed of nations willing to engage in the fight against terrorism, devoted to the value of freedom, and ready to contribute to the common defense.

"The new expanded alliance should be open to any free, security-providing country whose liberty is threatened by extremists, terrorists, despots, and rogue nations. America's allies fighting in Afghanistan and Iraq are good first candidates." As the United States looks for ways to rebuild its global leadership, Mr. Holmes argues, a new set of institutions will be needed. A Global Freedom Alliance could indeed be a powerful force for good in the new security environment that we find ourselves.

What has to be thought through is whether NATO can "go global" without loosing the regional benefits it continues to provide in Europe. NATO still remains the strategic political and military link between the United States and Europe, and it continues to have a stabilizing effect on the European continent as a security guarantee for its new members. We should not lose sight of those core missions.

Helle Dale is director of the Douglas and Sarah Allison Center for Foreign Policy Studies at the Heritage Foundation.