By Sally McNamaraHeritage Foundation

When President Obama celebrates NATO's 60^thbirthday in Strasbourg and Kehl, he should raise a toast to the transatlantic security alliance, which has helped keep the peace in Europe since the end of the Second World War.

NATO played a major role in winning the Cold War and defeating the evil empire. It has now enlarged to take in former Soviet-oppressed nations from the Baltics to the Balkans. It is the world's most successful multilateral alliance and a vital component of the global security architecture, providing stability from Athens to Ankara, from Pristina to Paris.

It is vital that President Obama continue to support America's commitment to NATO and that he emerge as a strong leader within the 60-year-old alliance at the summit.

However, threats and challenges still exist, and President Obama needs to address these threats during this Summit. His top five agenda items must be:

1. Rally Support for the NATO Mission in Afghanistan

When NATO invoked its sacred Article V for the first time, on Sept. 12, 2001, it implied that the 9/11 attacks on the United States represented an attack on the entire alliance. Since then, London, Madrid and Istanbul have also suffered at the hands of Islamist terrorists, and the mission in Afghanistan therefore stands as a central front in the long war on Islamist terrorism. President Obama must make clear to Europe that the mission in Afghanistan is no more a mission of choice for them than it is for the United States; that it is a mission of necessity and failure is not an option. Continental Europeans must step up to the plate in Afghanistan by committing more combat troops with fewer national caveats, and adequately contribute to a comprehensive plan for victory.

2. Uphold the Primacy of NATO in Europe's Security Architecture

French President Nicolas Sarkozy has stated his intention to fully rejoin NATO command structures at the summit. In return, he has received American support to develop a European Union defense identity separate from NATO's. At a time when defense resources are becoming scarcer and competition for them fiercer, it makes no sense to create a duplicate, Europe-only military alliance on the Continent. The militarization of the European Union embodies the worst elements of European animosity toward the United States and has created uncertainty about the primacy of NATO in European security affairs. Therefore, President Obama should reaffirm NATO as the cornerstone of the transatlantic alliance and the primary actor in European security.

3. Reaffirm Support for NATO Enlargement

Just a decade on from their troubled pasts, Croatia and Albania will sit at the summit table as full members of the NATO alliance. This is an extraordinary achievement, and stands as testimony to the powerful incentives offered by NATO membership.

The alliance should take heed, and President Obama should reaffirm the position he took while in the Senate that Georgia and Ukraine be admitted into NATO's Membership Action Plan. Russian intimidation of its near neighbors must not be tolerated, and NATO should instead embrace the Euro-Atlantic aspirations of all European democracies.

4. Reaffirm Support for Missile Defense

On two separate occasions, NATO has specifically endorsed the deployment of U.S. missile defense installations in Poland and the Czech Republic. At the Bucharest summit in April 2008 and the Foreign Ministerial summit in Brussels in December 2008, the final communiques recognized the value of missile defenses in countering ballistic missile proliferation and the "substantial contribution to the protection of Allies from long-range ballistic missiles" that the third site deployment would provide. President Obama must stop sending mixed messages over the deployment and conclude the third site missile-defense deal with Prague and Warsaw, as well as challenging NATO to form a comprehensive, layered missile defense for the entire alliance.

5. Elect a New Secretary General

Despite a strong campaign by Poland's foreign minister, Radek Sikorski, a majority of alliance members, including France, Germany, Britain and America, have thrown their weight behind Denmark's prime minister, Anders Fogh Rasmussen, for NATO's top civilian post. The current Secretary General, Jaap de Hoop Scheffer, will leave office on July 31, 2009. In light of NATO's packed agenda, it is important that a replacement is found sooner rather than later.

It is vital that President Obama continue to support America's commitment to NATO and that he emerge as a strong leader within the 60-year-old alliance at the summit. The United States will need its strongest and most enduring allies to confront the many dangers of global instability. It also needs a president confident of America's leadership role in the world.