Alliance History and the Future NATO: What the Last 500 Years of Alliance Behavior Tells Us about NATO’s Path Forward


Given the significant changes in the global security environment over the last 20 years, NATO now finds itself mired in divisive debates concerning identification of threats and the expenditure of resources to deter or defend against them. Because of the alliance’s debilitating activities many opine that it is on the road to divergence and ultimate dissolution. Yet despite these frictions and criticisms, NATO continues to attract new members and missions – indicating there may be more value to be found in this 61-year-old organization.

This paper attempts to identify a path forward for NATO by first examining the history of alliances – why they are formed and what makes them disband – and then, using insights gained from history, evaluates NATO’s state against these objective rationales. It goes on to examine the base purposes of military alliances, and how these apply, if at all, to NATO today.  Lastly, this paper identifies decisions that member nation leaderships should consider in determining the next state for the Alliance.

Examination of military alliances from the last 500 years finds that collective defense alliances disband soon after their threat, for which they originally banded together to deter or defeat, disappears. Specifically, 47 of the 63 major military alliances from the last 500 years disbanded.  Of those that dissolved, the greatest number of them – 40 total, included collective defense as one of their core purposes. And two-thirds of the alliances formed around a collective defense promise dissolved due to the elimination of the threat (or being vanquished by it).  Consequently, with the loss of NATO’s principal threat, the Warsaw Pact, and with no new like threat of that scale emerging to take its place, NATO’s role as a collective defense alliance is largely voided.  Hence, history predicts that the Alliance is likely to meet the same ill fate as the other collective defense alliances from the last five centuries.  

However, not withstanding NATO’s challenge to satisfactorily identify something to defend against, there continue to be significant roles that NATO can play to sustain and improve security for its members. For the last 20 years the NATO alliance has performed a myriad of security activities ranging from humanitarian assistance to peace and stability operations. While these activities did not directly support the direct collective defense of any NATO member, they have buttressed NATO’s ideological precepts of promoting democracy, individual liberty, and the rule of law.  Furthermore, benefit can be found in NATO’s continuing to sponsor the stabilization of its struggling neighbors in the Balkans and Eastern Europe.

For NATO to continue as a security alliance, it must reassess its purpose given the realities of the 21st century security environment and then amend its policies, structures, and capabilities to address them.  Only when its purpose is feasible and shared will the Alliance be able to avoid the divisive behaviors and lack of trust that stem from trying to apply 20th century state-on-state defense systems against the unconventional and often non-military risks of the 21st century.