In spring 2019, NATO foreign ministers gathered for a 70th anniversary summit and, once again, committed the Alliance to strategic relevance and impact.1 There is no comparable case of alliance longevity among sovereign countries—all other alliances in history have typically ended after the security threat they created to manage dissipated or was defeated. As the articles of this special issue make clear though, NATO continues tSo be a valuable security provider for its numerous member states. No country that has joined NATO has ever left it, and there continues to be a waiting list to get into the club. How has the alliance managed to not simply endure but to thrive over this lengthy time period? Several material and ideational factors compete to explain alliance duration, but individually these are only of limited utility in explaining NATO’s continued strength and vitality. Some scholars have attempted to build NATO-specifc models of endurance, but even these are of limited value. This article will assess NATO’s adaptation since 1990 to identify the key factors shaping, driving, propelling, and threatening NATO’s endurance. Whether NATO will make it to the 80th anniversary of its founding is likely to be a function of its ability to pursue what might be considered the traditional security agenda of collective defense while simultaneously pursuing a less traditional security agenda of crisis management beyond member state territory and cooperative security with partners in Europe and beyond. The central argument of this article is that explanations for NATO’s endurance must include consideration of the fact that the alliance’s missions, activities, and issue areas—what might be considered collectively NATO’s repertoire—have expanded over time, and that this expansion has been pivotal to convincing member states of the alliance’s enduring value. Generally, the expansion of NATO’s repertoire occurred in two phases. The first unfolded during the nearly quarter century of the post-Cold War period, from 1990 until early 2014 and Russia’s invasion of Crimea and eastern Ukraine. The second has been going on since 2014. In both periods, changes in the alliance’s repertoire reflected a combination of evolving interests of the member states and the addition of new member states with interests of their own. The paradox confronting the alliance and its member states is that it remains increasingly difficult from a material perspective for NATO to achieve its objectives in both spheres—that is, in terms of adequately deterring Russia and assuring the newest member states of Eastern Europe, while simultaneously meeting the security demands of other allies who fnd greater utility in NATO’s role outside the realm of territorial defense. To examine these issues further, this article will first briefly summarize NATO’s adaptation since the end of 1990, breaking down the last 29 years into two distinct period—the frst from 1990 until Russia’s invasion of Ukraine in 2014, and the second from 2014 to the present. The article will then turn to surveying what political science and history tell us about alliance duration, as well as what these fields have to say specifically about NATO’s endurance. Finally, the article will assess and analyze the historical record from these two time periods—and especially NATO’s willingness, if not ability, to expand its organizational repertoire—in an effort to better explain the alliance’s continued endurance.
In spring 2019, NATO foreign ministers gathered for a 70th anniversary summit and, once again, committed the Alliance to strategic relevance and impact.1 There is no comparable case of alliance longevity among sovereign countries—all other alliances in history have typically ended after the security threat they created to manage dissipated or was defeated NATO continues tSo be a valuable security provider for its numerous member states. No country that has joined NATO has ever left it, and there continues to be a waiting list to get into the club. How has the alliance managed to not simply endure but to thrive over this lengthy time period? This article will assess NATO’s adaptation since 1990 to identify the key factors shaping, driving, propelling, and threatening NATO’s endurance. Whether NATO will make it to the 80th anniversary of its founding is likely to be a function of its ability to pursue what might be considered the traditional security agenda of collective defense while simultaneously pursuing a less traditional security agenda of crisis management beyond member state territory and cooperative security with partners in Europe and beyond. The central argument of this article is that explanations for NATO’s endurance must include consideration of the fact that the alliance’s missions, activities, and issue areas—what might be considered collectively NATO’s repertoire—have expanded over time, and that this expansion has been pivotal to convincing member states of the alliance’s enduring value. . The first unfolded during the nearly quarter century of the post-Cold War period, from 1990 until early 2014 and Russia’s invasion of Crimea and eastern Ukraine. The second has been going on since 2014. In both periods, changes in the alliance’s repertoire reflected a combination of evolving interests of the member states and the addition of new member states with interests of their own. The paradox confronting the alliance and its member states is that it remains increasingly difficult from a material perspective for NATO to achieve its objectives in both spheres—that is, in terms of adequately deterring Russia and assuring the newest member states of Eastern Europe, while simultaneously meeting the security demands of other allies who fnd greater utility in NATO’s role outside the realm of territorial defense. Finally, the article will assess and analyze the historical record from these two time periods—and especially NATO’s willingness, if not ability, to expand its organizational repertoire—in an effort to better explain the alliance’s continued endurance.