Enduring, but irrelevant? Britain, NATO and the future of the Atlantic alliance

The continued endurance of the North Atlantic Treaty Organization (NATO) following the end of the Cold War has become a major puzzle for scholars of international relations (IR). Neorealist scholars expected NATO to become irrelevant and dissolve. Institutional, organizational and constructivist approaches to IR, however, argued that a number of various factors provided NATO with a firm foundation for the future. NATO did not disappear, but the past 20 years have been anything but easy for the organization. As the end of NATO's Afghanistan mission approaches, the alliance is once again confronted with the question, 'what next?' Increasingly miniscule European defence budgets and the 2011 military operation against Libya illustrate that NATO is now almost entirely underwritten by US power. Meanwhile, the United States is focused on the security of the Asia-Pacific region and its untenable budget imbalance, meaning that choices must be made. NATO may continue to endure, but is NATO still relevant? Can one still speak of an alliance, or has NATO evolved into something else? Were neorealist predications made in 1989 on the mark after all?