July 17, 1997
Specialist in European Affairs
Foreign Affairs and National Defense Division
Congressional Research Service
Library of Congress
Article V of the North Atlantic Treaty does not guarantee the use of force to assist an ally under attack. Nonetheless, the U.S. pledge to assist an ally under attack has been the core of the alliance. Despite growing political functions, the NATO views collective defense, and not collective security, as its core function.
A collective security organization settles disputes among its members. In contrast, a collective defense organization assists a member state under attack by an outside country. NATO is a collective defense organization. Article V states that NATO members must consider coming to the aid of an ally under attack. However, it does not guarantee assistance. Article V is the Treaty's key provision and the linchpin binding the United States to its NATO allies. It states, in part, that "an armed attack against one or more [allies] shall be considered an attack against them all." Additional language makes clear that the commitment to assist an ally is not unconditional. Rather, each signatory will assist the ally under attack with "such action as it deems necessary, including the use of armed force ......"(1) Since the early 1990s, NATO has begun to adopt "new missions," such as crisis management and peacekeeping, sometimes referred to as "non-Article V missions." Current members and candidate states, however, believe collective defense, as expressed in Article V, remains the core of the alliance, a view likely to endure as long as the possibility of a nationalistic, aggressive Russia remains.
Congress was reluctant to engage the United States in either World War. In each conflict, strong presidential advocacy and growing threats to broader U.S. interests led to eventual involvement. After World War 1, the U.S. Senate voted down the Versailles Treaty and, with it, involvement in the League of Nations because opposition remained strong to "entangling alliances." The protection offered by the Atlantic and Pacific Oceans contributed to the view that the United States still enjoyed a relatively unbridgeable barrier against attack.
The League of Nations Covenant, embedded in the Versailles Treaty, allowed but did not require signatories to use military force and economic sanctions against an aggressor. The League embodied the idea of "collective security," under which an international organization might seek to settle disputes among its members. President Wilson and other League supporters emphasized "the condemnation of public opinion" and "moral force" as key instruments in international affairs. Hitler's manipulation of public opinion and his intimidation of neighboring states made a mockery of such notions. Churchill, who urged military force against Germany from the early 1930s, taunted supporters of collective security and the League as guilty of "long-suffering and inexhaustible gullibility."(2) U.S. absence from the League left the institution without the strongest economic and military power after World War I, and therefore without effective leadership.
The global depression of the 1930s and the Second World War made clear that events in Europe greatly affected U.S. economic and political interests. From a desire to bring global stability, there was considerable support in Congress for the creation of the United Nations in 1945. Article 1 of the U.N. Charter outlined a resolve "to maintain international peace and security, and... take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression." Article 51 stated the "inherent right of individual or collective self-defense if an armed attack occurs...." A unanimous vote in the Security Council was necessary for a collective response, and the Soviet Union blocked meaningful U.N. action in the early years.
In the late 1940s, continuing instability in Europe led Congress and President Truman to move towards clear engagement in European security. The Soviet Union's blockade of Berlin, a Soviet-backed coup in Czechoslovakia, and a civil war in Greece with communists pitted against a democratic government were key events arousing U.S. efforts to construct a security edifice.
In 1948, Sen. Vandenberg, previously an isolationist, sponsored a resolution stating that the United States should pursue the "progressive development of regional and other collective defense arrangements for individual and collective self-defense" in accordance with the U.N. Charter. The Senate Foreign Relations Committee approved the resolution, which passed, and issued a report on the proposed North Atlantic Treaty that strongly endorsed collective defense. The Senate approved the Treaty, which went into force August 24, 1949.(3)
The Foreign Relations Committee report recommended "U.S. association with arrangements for collective defense" but laid down three conditions for U.S. involvement. First, U.S. contributions to collective defense "must supplement, rather than replace, the efforts of the other participants on their behalf." This condition, frequently noted in Senate debate in succeeding years, meant that allies must contribute significant forces to their own defense, so that the United States would not bear the brunt of the burden. Second, a President must follow "constitutional processes" for the United States to become involved in any security arrangement or conflict, a signal that the Senate wished to exercise its duty to give advice and consent to defense arrangements that might commit U.S. forces to war. Third, for the United States to fulfill a collective defense commitment, U.S. national interests must clearly be affected.(4)
From NATO's early days, the role and size of U.S. forces in Europe were keys to ensuring the viability of Article V. Only small contingents of U.S. conventional forces were in Europe at NATO's origins in 1949. The outbreak of the Korean War in 1950 and western Europe's continuing economic weakness and political instability led President Truman to send more U.S. forces to the continent. In the early 1950s, there was strong opposition in Congress to the policy of sending large-scale U.S. forces to Europe, given the long-expressed sentiment that the United States should "supplement, rather than replace" allied forces. Presidents Truman and Eisenhower eventually prevailed in their desire to maintain a sizeable U.S. force in the European theater. U.S. officials, seeing a growing Soviet threat, desired a contribution of West German economic and military potential to the alliance. West Germany joined the alliance in 1955.
The development of nuclear arsenals by both the United States and the Soviet Union complicated the debate over collective defense from the 1950s through the end of the Cold War. Through the mid-1950s, the United States had a larger and more sophisticated nuclear arsenal than the Soviet Union, while the Warsaw Pact was thought to maintain conventional superiority. However, by 1960, the Soviets' successful space program and their development of a large bomber fleet and missile force clearly signaled that the continental United States was vulnerable to nuclear attack in any conflict originating in Europe. The European allies sought reassurances that the United States "would trade Washington for Moscow" if war again came to Europe.
In 1967, under U.S. leadership, the alliance formulated the doctrine of "flexible response," by which NATO would use whatever means necessary to deter or repel a Soviet attack. Conventional forces would be initially engaged, but the United States pledged that it would use its strategic nuclear arsenal to defeat the Warsaw Pact if conventional forces failed in the defense of western Europe. Succeeding U.S. administrations and Congress consistently urged the allies to increase their conventional forces as the principal means to defeat a Soviet attack and avoid the calamity of a nuclear conflict. In 1978, for example, the alliance agreed upon a non- binding pledge to increase defense spending by 3% a year in order to strengthen conventional forces; this commitment was only irregularly met by the allies. Several factors contributed to the Europeans' failure to strengthen their conventional forces: the presence of significant political groupings that viewed increased defense expenditures as provocative in an already tense international atmosphere; economic strictures; and the stationing, by 1980, of over 300,000 U.S. forces that carried a significant part of the burden. Conventional forces were expensive to maintain, and nuclear forces were relatively inexpensive. Both France and Britain had nuclear arsenals, which their political leaders believed contributed to deterrence.
Some observers continue to believe that "flexible response" was essentially a myth. In the view of one prominent analyst, "the attempt to deter conventional aggression in Europe with a nuclear arsenal controlled by a non-European power [the United States] that is itself subject to nuclear retaliation has never appeared to be an example of political or military rationality."(5) Nonetheless, in the view of many strategists, the U.S. threat to use nuclear weapons served to create sufficient doubt in the minds of Soviet leaders to deter an attack. The United States deployed some of its nuclear weapons in forward areas, such as West German territory, to signal the Warsaw Pact that they might be used early in a conflict. The presence of significant U.S. conventional forces was itself a component of the philosophy of deterrence: Washington, in this view, would never allow U.S. troops to be overrun, and would ultimately defend them with nuclear systems, if the need arose.
U.S. nuclear systems in Europe were a step on the ladder of flexible response. Strategically, the United States and its allies sought to enhance the link between U.S. forces in Europe and the U.S. strategic nuclear arsenal with the 1979 alliance decision to base U.S. intermediate nuclear forces (INF) in Europe. The forward deployment in Germany (and elsewhere) of these mobile and highly accurate missiles was meant to signal Moscow -- and reassure the allies -- that these systems, controlled by the United States, could be employed to defeat a Soviet invasion.
Doubts over the U.S. commitment to Article V endured throughout the Cold War. The Strategic Defense Initiative (SDI), proposed in 1984, provoked criticism that the Reagan Administration wished to create a system that could shield the United States, but not its allies, against nuclear attack. In the language of the era, Europeans viewed SDI as "decoupling" the link between the United States and western Europe. Reagan Administration officials countered that SDI, by protecting the United States from nuclear attack, made easier any necessary decision in a conflict to use nuclear systems against the Soviets.
The collapse of the U.S.S.R. and the current disarray of the Russian military have eliminated any significant threat to western Europe and the United States. NATO has developed "new missions" relating to crisis management. Virtually all U.S. nuclear systems have been removed from Europe; only a few hundred nuclear gravity bombs, of limited military utility, remain. Official NATO doctrine does not describe Russia as an enemy, nuclear systems are no longer targeted on Russia, and nuclear weapons are now for use only in a "last resort" -- a different formulation from flexible response, where such weapons were strategically mixed with conventional forces and might be used where appropriate to defeat a Soviet attack.(6)
The Soviet threat bound the allies together. The risks that have replaced that threat have given rise, in the view of some observers, to a "regionalization" in NATO that could undermine the viability of Article V. Countries in one region of the alliance are concerned about dangers inherent in their geographic neighborhoods that may not directly affect allies in a distant corner of Europe. In 1991, there was a concrete example of regionalization. When Turkey agreed to lend its bases as a staging area for airstrikes against Iraq in the Persian Gulf War, Turkish officials indicated that they might invoke Article V if Iraq retaliated. Initially, the German government was sharply critical of U.S. efforts to expel Iraqi forces from Kuwait. Otto von Lambsdorff, then a key figure in the German coalition government, said in response to the Turkish inquiry, "We are convinced that a missile attack on Turkish territory does not require a NATO response." Some members of the German Bundestag contended that it was Turkey, by allowing U.S. aircraft to attack targets from Turkish bases, that had acted provocatively, and that Germany must not honor any request from Ankara for assistance.(7)
The Administration continues to describe collective defense as the core of the alliance. Before the Senate Armed Services Committee on April 23, 1997, Sen. Kempthorne asked: "...if NATO is not anti-Russian, then what is it? Who is the alliance defending against?" Secretary of State Albright responded:
The threat is basically ... the instability within the region which has in fact created two world wars. But there is also the possibility of an outside threat. There is a possibility of threats from various parts outside the region, to the south, that we have to guard against. And, on the off chance that in fact Russia does not turn out the way we are hoping it will and its current leadership wants, NATO is there.(8)
Some observers believe that the importance of Article V, in the absence of a Russian threat, is at least temporarily diminished. They express concern that the growing importance for NATO of non-Article V missions is making the alliance more a collective security than a collective defense organization. "Regionalization," in this view, could dilute the effectiveness of the alliance. NATO's mission in Bosnia has not been undertaken to respond to or prevent an attack on an ally, but rather as "crisis management." Reaching unanimity for the long term in bringing stability to Bosnia is proving difficult. Some allies see an element of "regionalization" in enlargement of the alliance. Officials from Italy, Greece, and Turkey, for example, have stronger concerns about stability in the Balkans than do the Norwegians or the Danes. In the debate over enlargement, Rome, Athens, and Ankara supported the entry into NATO of Slovenia and Romania as a means to assure stability; the Nordics opposed the candidacies of these two countries, and the Danes urged the admission of the Baltic states.(9)
NATO remains an organization geared for collective defense, and leaders of NATO states point out that the Organization for Security and Cooperation in Europe (OSCE) serves the purpose of collective security through such actions as monitoring human rights, arbitrating conflicts, and overseeing elections in selective member states. NATO, in contrast, insists that candidates for membership resolve ethnic and border conflicts before entering the alliance. An exception to this rule has been NATO's effort to manage tensions between Greece and Turkey, both alliance members.
Agreeing upon a cohesive response to threats short of war is difficult, due to geography, political traditions, and economic need. Article V raises the possibility of a range of responses to counter a threat: An ally may take "such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area." Presumably, such action could be an economic embargo or other steps, short of force, to compel a state threatening an ally to adopt a more benign policy. Some Administration officials are discussing nuclear proliferation with candidate states as a threat that could cause Article V to be invoked. It is not clear that all allies would agree that Article V is appropriate for such a threat. At the same time, the important difference from the era of "collective security" between the World Wars is that the United States is clearly engaged in Europe as NATO's leader, and maintains the capacity to deter or defeat an adversary that threatens an ally's survival.
(1) Article V states, in full: "The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all and consequently they agree that, if such an armed attack occurs, each of them, in exercise of the right of individual or collective self-defense recognized by Article 51 of the Charter of the United Nations, will assist the Party or Parties so attacked by taking forthwith, individually and in concert with the other Parties, such action as it deems necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area. Any such armed attack and all measures taken as a result thereof shall immediately be reported to the (U.N.) Security Council. Such measures shall be terminated when the Security Council has taken the measures necessary to restore and maintain international peace and security."
(2) For a contemporary view, see E.H. Carr, The Twenty Years' Crisis, 1919-39, (New York, 1939).
(3) See North Atlantic Treaty, Senate Foreign Relations Committee Report. 81st Congress, 1st sess. Washington, June 6, 1949.
(4) Ibid., p. 78.
(5) Lawrence Freedman, "NATO Myths," in George Thibault (ed.), The Art and Practice of Military Strategy. Washington, NDU Press, 1984. p. 692.
(6) See Library of Congress. CRS. NATO Nuclear Strategy. Issues for U.S. Policy, by Stanley R. Sloan. CRS Report 96-653. July 25, 1996.
(7) "Germany reluctant to defend Turkey if Iraq retaliates," Washington Post, Jan. 22, 1991. p. A20. Ultimately, Chancellor Kohl sent aircraft to Turkey to be used to defend Turkish airspace, but not for attack against Iraq.
(8) "Hearing on NATO Enlargement," Senate Armed Services Committee. April 23, 1997. unpaginated manuscript.
(9) See Library of Congress. CRS. NATO Enlargement: Process and Allied Views, by Paul E. Gallis. CRS Report 97-666. p. 14-20.