President-elect Barack Obama should make history. Not just on Jan. 20, but on April 4, as well. The latter date marks the 60th anniversary of the North Atlantic Treaty Organization, or NATO.

When Harry Truman signed the North Atlantic Treaty six decades ago, he observed, "Events of this century have taught us that we cannot achieve peace independently. The world has grown too small."

The words still ring true, but the world has changed. NATO must change, too, if it is to meet the challenges of the 21st century.

The alliance's 60th anniversary celebration is the perfect occasion for Mr. Obama to announce a new vision for NATO.

The United States must take the lead in revitalizing the geriatric organization. It's the only country in the alliance that can still walk and chew gum at the same time. Less than a handful of the other member states invest in defense at a rate anywhere close to the agreed-upon target: a paltry 2 percent of gross domestic product (GDP).

Increasingly, NATO is in danger of becoming a paper tiger. Its mission in Afghanistan would certainly fail if the U.S. were not shouldering far more than its share of the burden.

Meanwhile, the alliance itself faces fierce competition from a surprising source: The European Union. Many European nations hold membership in both NATO and the EU. They often "double count" their forces to meet commitments to both. That's fine, as long as NATO and the EU decide to fight the same war. Unfortunately, NATO and the EU do not always see eye to eye institutionally.

Finally, many NATO countries are feeling pressure from a resurgent Russia. This week, the Kremlin reminded Europeans exactly who controls much of the natural gas and oil they burn - by cutting gas supplies 20 percent. The none-too-subtle exercise of power was well-calculated to fray ties among anxious allies.

A better interest4573-9E8D-EDEB3C39A838}">interest, too. Twenty-first century threats are international in character and indeterminable in length. They require a united, international response. And the best allies are not those of temporary convenience, but alliances based on an enduring commitment to peace, justice, security and -- above all -- freedom. Most of the nations that share these goals with America are in NATO.

Building strong alliances requires a proactive strategy -- one that reinforces, rather than undermines, the sovereignty of individual states, while at the same time strengthening the bonds of trust and confidence between free peoples. This approach enables alliance members to act in their common interest.

A plan for NATO 2.0 has to start with pushing for agreement about threats facing the alliance and how to respond. The biggest threats today -- such as terrorism, cyberwar and ballistic-missile attack -- weren't even on the radar screen in Truman's era.

The alliance must also reaffirm its commitment to bringing in new members. Seeking to mollify the Kremlin, some European nations want to give Russia nation-by-nation veto power over NATO expansion. That would destroy the alliance's credibility. NATO needs an unequivocal "open-door" policy for nations sharing a commitment to freedom and other core values of the allies, even ones outside Europe proper - Israel for example.

NATO also needs much more flexible decision-making. Currently, nothing gets done unless everyone agrees. Group decisions should not require unanimity. States should be able to pursue allied missions under the NATO flag even if some members don't participate. Moreover, only those countries that substantially contribute to a mission (with troops and other resources) should be involved in the planning and execution.

The U.S. also ought to press for an unambiguous division of NATO/EU responsibilities, one that leaves NATO the supreme role in trans-Atlantic security. The EU should serve as a civilian complement focusing on constabulary missions (like combating piracy) and non-military "soft power" (such as election monitoring and public diplomacy). The EU excels in these functions, but not at defense.

There should also be new burden-sharing rules. Specifically, the benchmark for defense spending (at least 2 percent of GDP) should be made an enforced requirement. It should be an entry requirement for countries seeking admission, to make sure they are bringing something to the table. (Without it, they become a defense liability, rather than an asset.) And members must continue to measure up on investment if they wish to retain full voting rights within the alliance.

These are tough rules for a new vision. Doubtless they would encounter a lot of balking. But pushing them through would both reaffirm our commitment to making the alliance work and reassert American leadership within the alliance.

Making NATO bigger, better prepared, more cohesive and more flexible in dealing with emerging threats would be a truly historic achievement.

Mr. Obama could get the ball rolling on April 4, just 10 weeks into his presidency.

James Jay Carafano is a senior fellow at The Heritage Foundation and the author of GI Ingenuity: Improvisation, Technology and Winning World War II.