Afghanistan was the first test for NATO's new role as an expeditionary power. Though the alliance had been involved in Bosnia and Kosovo in the 1990s, the NATO mission in Afghanistan was its first major military effort outside of Europe. In the years that followed, and as the group began to control operations in other parts of the country, the mission in Afghanistan also exposed many of the problems of NATO's renewed 21st-century existence.
One issue was that the perception of the global terrorism threat has evolved significantly among NATO countries over the years. From 2001 until the present day, many European nations have perceived terrorism as more of a threat to America, says Miles Pomper, a research associate at the Center for Nonproliferation Studies in Washington. As a result, there have been very mixed views about NATO's efforts to fight terrorism in Afghanistan and elsewhere. The conflict has also demonstrated gaps in the various countries' involvement, overall capacity, and commitment of resources.
Still, the mission in Afghanistan served as proof that the alliance could work, and some, like Burns, would argue that the conflict has indeed made the alliance stronger. Though not all NATO countries participated militarily in heavy combat areas, they have all contributed in some way in Afghanistan. "Even if there are fundamental differences in how people view the nature of the threat, the fact that they are able to work through those differences is a sign of strength, not weakness," says Lewis. "If the alliance were weaker, we would never have been able to do Afghanistan at all."
Also, for many nations, Afghanistan was also a chance for many countries to put their military into action for the first time in decades. The alliance coordinated military operations, improving practically and technically along the way, despite the nations' different views on the conflict.
However, Iraq was a different story, splitting the alliance where Afghanistan had brought it together. "NATO allies disagreed over whether it was a good thing to do, and it made lots of European countries more hesitant to work together with the U.S. on security issues because they were unhappy with Iraq," says former U.S. NATO Ambassador Kurt Volker, now a senior fellow at the Johns Hopkins School of Advanced International Studies. "So it had an impact on the alliance, even though it wasn't an alliance mission."
Iraq was the turning point for the alliance, says Nikolai Sokov, senior fellow at the Vienna Center for Disarmament and Non-Proliferation, part of the Monterrey Institute's Center for Nonproliferation Studies. The United States going into Iraq dissipated much of NATO's energy for the fight against terrorism. "We squandered a lot of potential," he says. "Terrorism is no longer as unifying an agenda as it was [immediately] after 9/11."
Apart from the mission in Afghanistan, many counterterrorism efforts since September 11—such as intelligence sharing and law enforcement—have been conducted unilaterally or bilaterally, rather than through the military apparatuses of NATO. And rather than NATO itself, it's been the partnerships with non-NATO countries, especially in the Arab and Muslim world, that have often proved more useful in addressing the decentralized problem of terrorism, according to Pomper. "In the war on terrorism, the key countries aren't really NATO countries, they're Arab countries or countries with large Muslim populations," he says. "It's a military alliance. It's not necessarily the best instrument to deal with law and order and crime and case issues."
More recently, as allied forces remained in Afghanistan and the threat of terrorism persisted, the intervention in Libya this year showed that a decade after it expanded its reach after 9/11, NATO remains an effective force outside its own territory. "It was a proud moment in NATO history," says Burns.