On April 4, 1949, representatives from twelve countries - Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom, and the United States - gathered in the Grand Auditorium of the US State Department and affixed their signatures to the North Atlantic Treaty (sometimes known also as the Washington Treaty). Unbeknownst to its drafters, the succinct four-page document would give life to the North Atlantic Treaty Organization (NATO), forge a relationship between the signatories, and play an integral role in shaping the global politics of the next seven decades.
At its core, the NATO alliance is predicated on a belief in collective defense. As signatories to the Washington Treaty, member states agree to maintain their individual capabilities to defend themselves, as well as to contribute to collective resources to be used in the case the alliance is called to action. Further, allies commit to careful monitoring of shared threats and close consultation on threats to the security of all NATO members. Member states agree to not become parties to alliances, treaties, or other binding arrangements that directly conflict with the security interests of other NATO allies. Most prominently, the collective defense doctrine is illustrated in Article 5 of the Washington Treaty, which commits all member states to action in the event of an armed attack against a NATO member.
Although the alliance has only ever formally invoked the Article 5 provision once (in the wake of the terrorist attacks on the United States on September 11, 2001), the organization has been guided by the principles of collective defense since its inception. NATO's first Supreme Allied Commander (SACEUR) Dwight D. Eisenhower set about building the military structures needed for the alliance to engage in the Korean War, while others worked with states like Turkey, Greece, and Western Germany to shore up not only each country's security but also future commitment to liberal democratic principles and eventual NATO membership.
NATO also played an integral role in global discussion and debate over nuclear weapons, especially in the first half of the Cold War. Although it was the first, the United States was not the only ally to possess nuclear weapons; the United Kingdom and France had burgeoning nuclear programs during WWII, and their nuclear ambitions were realized in 1952 and 1960, respectively. Recognition of the immense power of nuclear weapons and the imminent danger of Soviet nuclear expansion during such a tense period led the alliance to embark on a number of initiatives. First, the alliance sought to develop specific plans in the event of a nuclear attack through what is known today as the Nuclear Planning Committee. Second, nuclear armed powers sought to reassure nonnuclear allies of their commitment to protect and defend against hostile nuclear states (sometimes referred to as a 'nuclear umbrella'). They did so by not only political agreement (known as 'nuclear sharing' within NATO) but also in their actions. American nuclear weapons were deployed to strategic locations all over the globe, including in NATO states such as Britain, France, Italy, West Germany, Turkey, the Netherlands, Greece, and Belgium. Third, both nuclear and nonnuclear allies played an integral role in crafting an international regime on nuclear weapons, characterized by international treaties such as the Nuclear Nonproliferation Treaty (NPT) and several bilateral agreements between the United States and the Soviet Union (and later Russia), because of the threat posed from the proximity of nuclear adversaries and the shared belief in mutually assured destruction.
The NATO alliance was formed and continues to operate as a regional, exclusive, military organization. However, scholars point to both its treaty and its original members as evidence that the alliance was to operate as part of a broader range of international organizations and institutions grounded in shared principles - principles which are considered to be at the foundation of Western liberalism. The Washington Treaty makes several references to the United Nations (UN) and values enshrined in the UN Charter: peaceful mitigation of threats to international peace and security whenever possible, good-faith efforts to transparently and diplomatically settle interstate disputes, close consultation with all pertinent UN bodies, and the use of force as an absolute last resort. The Washington Treaty also espoused the values for which member-states should stand ready to defend, including "the principles of democracy, individual liberty and the rule of law." The most famous remarks of NATO's first Secretary General Lord Hastings Ismay regarding NATO's purpose to "keep the Americans in, the Russians out, and the Germans down" refers not only to great power politics but also to the alliance's efforts to prevent the retrenchment of nationalism in Europe and foster a collective identity amongst the transatlantic partners. Thus, by becoming members of the NATO alliance, states committed to upholding the principles of the United Nations (and subsequently Western liberalism) both within their own states but also within the international community.
While the end of the Cold War brought tremendous change to the international system, including the dissolution of the Soviet Union and the USSR's own collective defense organization the Warsaw Pact, and the emergence of new states who would become future members of NATO, threats to the allies' security as well as international peace and security more broadly persisted. Despite no longer facing imminent danger from the Soviet Union, NATO went from waiting in the wings to center stage in engaging in numerous missions in and around Europe and the United States. In the 1990s, NATO undertook missions in Kuwait and Turkey during the Persian Gulf War, patrolled the Central Mediterranean, provided assistance to Russia and other former Soviet satellites, and spearheaded operations during the conflict in the Balkans, first in Bosnia and later in Kosovo. In addition to its invocation of Article 5 in support of the United States after the 9/11 terrorist attacks, NATO was vital in its leadership of the International Security Assistance Force (ISAF) in the war in Afghanistan. First as a partner and later as its leader, NATO engaged in Libya during the 2011 Arab Spring. NATO also played a number of smaller roles during the US war in Iraq and sustained broader-range missions in places like the Horn of Africa and the Mediterranean to combat threats such as trafficking and terrorism.
NATO today consists of 29 members: all of the original signatories to the Washington Treaty have remained, while newer members include not only more Western European countries but also several former Soviet Republics. Contributions to the alliance take two forms. By being members of NATO, states agree to invest in their military institutions and resources so as to be able to provide for their own security. These "contributions" remain under the purview of the individual states. Additionally, allies contribute both monetary resources to fund the NATO budget and nonmonetary resources to support NATO missions and other initiatives.
Just as the alliance enjoys two types of contributions, it maintains two primary sets of structures: a civilian structure and a military structure. Headquartered in Brussels, Belgium, the North Atlantic Council (NAC) is led by the Secretary General and is comprised of the highest-level representatives from each ally, who vary based on the issue at hand. NATO headquarters is also the home of thousands of civilians working as part of the international staff representing the organization as a whole (not their home state delegation). In addition to maintaining an international military staff, the military structure is comprised of the Allied Command Transformation (ACT) and Allied Command Operations (ACO). ACT, situated in Norfolk, Virginia, USA is tasked with comprehensively ensuring the alliance's ability to respond to an ever-evolving threat environment. The Supreme Headquarters Allied Powers Europe (SHAPE) in Mons, Belgium, is home to ACO activities, the most conspicuous of which includes directing all alliance military operations.
In 2019, NATO continues missions in Afghanistan, the Mediterranean, and Kosovo, all the while looking to other areas of concern and preparing for various types of missions and needs. Major areas of focus including countering terrorism, defending against nefarious activities in the cyber realm, anticipating emerging challenges stemming from climate change in areas such as the Artic, and responding to humanitarian crises at home and abroad, be it egregious violations of human rights or mass flows of people displaced by war, natural disaster, or other means. Debate continues over whether the alliance should engage outside its primary area of concern (Europe and North America) in light of Russian actions in many different states and the 2014 illegal annexation of Crimea, which led NATO to suspend for a time its NATO-Russia Council activities. Until productive dialogue can resume, allies fear an aggressive Russia threatens the interests and sovereignty of NATO members. The alliance also faces internal challenges: while not unprecedented, conflicts over burdensharing (for example, between the United States and the European allies), the appropriateness of NATO action, governance, and non-NATO partnerships disrupt efforts to improve alliance cohesion and could threaten the alliance's longevity. Still, there is hope: the alliance has faced similar challenges throughout seven decades of operation, yet remains not only a prominent actor in international relations but also one of the most institutionalized multilateral alliances in history.