After the Austrian peace treaty in April and the admission of West Germany to NATO in May 1955, the Geneva Four-Power Summit in July inaugurated the first thaw in East-West relations. Although neither the summit conference nor the subsequent Geneva foreign ministers' conference managed to solve any of the many outstanding Cold War problems, the two meetings led to a more relaxed international climate. It appeared to be possible to contain the Cold War in Europe peacefully and agree to disagree, something that was soon called "peaceful coexistence."
Although East-West relations deteriorated temporarily when the Soviet Union invaded Hungary in late 1956, the almost simultaneous Anglo-French-Israeli attack on Egypt to reverse nationalization of the Suez Canal shook the Western alliance to its foundations. American anger at not having been consulted and Washington's fear that the British-French action would open the doors of the Middle East to the Soviet Union (as it did) led to the first occasion when the United States and the Soviet Union sided against two western European countries. An American-inspired run on the pound sterling and the effective imposition of an oil embargo on Britain by President Eisenhower had the desired result. Britain gave notice to the French that they would have to withdraw from Egypt, an action that caused a great deal of anti-British resentment in Paris. The Suez crisis made it clear that Britain and France, who still retained a good deal of global influence, were not able to embark on independent international action without the approval and support of the United States. Thus the crisis symbolized the decline of western Europe to the status of a mere satellite continent.
After the Suez crisis American preponderance within the Western alliance, both in its political and strategic dimension, could no longer be doubted. The Europeans increasingly became reactive members who criticized and complained while most constructive initiatives originated in Washington. This was evident during the long Berlin crisis of 1958–1963, which led to a quite unexpected escalation of the Cold War and to the building of the Berlin Wall in August 1961. The Berlin crisis and in particular the October 1962 Cuban missile crisis brought the world close to nuclear war. The August 1963 limited test ban treaty between the United States, the United Kingdom, the Soviet Union, and any other state that wished to join was one of the lessons drawn from the missile crisis. Another was the installation of a "hot line" between Washington and Moscow.
Despite the increasing Cold War marginalization of Europe in the second half of the 1950s and during the 1960s, European alliance members played a subordinate but still significant role with regard to the development of NATO's strategic concepts. However, most initiatives came from the United States. Shortly after taking office the Eisenhower administration realized that the conventional force goals as agreed at Lisbon would either remain unrealistic or, if implemented, would undermine American and European economic competitiveness and social well-being. Thus, Washington invented vague concepts with names such as "long haul," "massive retaliation," and "new look," which would obscure the fact that the alliance was unable to develop as quickly and as intensively as originally envisaged.
Although the European alliance members were very critical of the increased reliance on nuclear containment, there was very little they could do. While always prepared to criticize American proposals, NATO's European members were not prepared to put more of their own scarce resources into developing their conventional forces. The only concept they partially agreed with was the "long haul" idea, which essentially consisted of the insight that the frantic rearmament efforts of the Korean War and Lisbon conference era could not be sustained for financial and psychological reasons; the plan was therefore to be stretched out over a longer period of time. However, "massive retaliation" and the "new look," as first outlined in NSC document 162/2 in late 1953, were very different matters. Because the envisaged conventional rearmament goals were unrealistic and because the production of atomic weapons appeared to be a lot cheaper than conventional warfare methods, the Eisenhower administration intended to focus NATO's strategy on nuclear containment. U.S. officials argued that fear of an American atomic response would prevent any Soviet attack on the countries of the Western alliance. Moreover, getting "greater bang for the buck," as Eisenhower's secretary of defense expressed it, would ensure the maintenance of healthy Western economies and budgets.
The increasing reliance on nuclear diplomacy meant that NATO would have no choice but to respond with atomic weapons if, for example, the Soviet Union invaded West Germany. NATO was all but incapable of retaliating to a communist attack with conventional weapons. Instead it would rely on the so-called "trip-wire" idea: once the Soviet Union attacked Europe and the U.S. soldiers stationed there, Washington's Strategic Air Command would be activated. The implications of such a scenario were most disconcerting for the West Germans and their European neighbors. The Joint Chiefs of Staff Admiral William Radford's 1956 suggestion, as leaked to the New York Times, that the United States needed to reduce U.S. troops in Europe to two million by the withdrawal of 800,000 soldiers from the continent, gave rise to great concern. Moreover, the greater the arsenal of intercontinental nuclear weapons at the disposal of the Soviet Union, the larger the question mark in the minds of European leaders about whether or not Washington would be prepared to run the risk of inviting a Soviet attack on American territory by coming to the aid of Europe.
This became a realistic concern in 1957, when Moscow sent Sputnik, the first space satellite, into orbit and also managed to launch the first intercontinental ballistic missile. American cities, and not merely European ones, could now be reached by Soviet nuclear bombs. Soon politicians were talking about a "missile gap" to the detriment of the West; this dominated the U.S. election campaign of 1960, although it soon became known that Nikita Khrushchev had been vastly exaggerating the Soviet Union's nuclear capabilities. Still, Sputnik contributed to the fact that the U.S. government was more than ever in favor of "burden sharing" within the alliance. While the United States would be responsible for enhanced nuclear containment, Washington expected the western Europeans to provide for the cost-intensive conventional means of defending the European continent from any Soviet invasion. However, much to the irritation of the United States, the Europeans were both unwilling and economically unable to dedicate the expected resources to the defense of the Western alliance.
American politicians also became increasingly uneasy about the military implications of "massive retaliation." In the last few years of the Eisenhower administration and in particular with the advent of the Kennedy administration in January 1961, U.S. officials considered plans for replacing this doctrine with a new NATO strategy. Initially, they developed the concept of a shield force, which would include troops equipped with tactical nuclear weapons as well as conventional arms. The administration attempted to persuade Congress that nuclear sharing with the NATO allies, in particular with Britain, was essential for maintaining NATO's credibility. In 1958 this resulted in the repeal of the 1946 McMahon Act, which had forbidden the sharing of nuclear secrets with either friend or foe. In late 1962 it also helped British prime minister Harold Macmillan argue his case with President Kennedy that the canceled Skybolt missile be replaced with American Polaris missiles that the British could equip with their own nuclear warheads. The French were offered a similar deal but turned it down. Under President Charles de Gaulle, France would later insist on military independence.
A new strategic concept, "flexible response," was eventually adopted in 1967. It was meant to allow NATO to respond to an invasion by the Soviet Union with a range of escalating options: use of conventional weapons, use of small tactical atomic weapons, and only finally initiation of a full-scale nuclear war. But this also was a controversial concept. The European NATO allies generally feared that a Soviet and eastern European attack at multiple locations and by multiple means would still give the Western alliance no option but to embark on escalating the conflict into a nuclear counterattack. Moreover, the question remained: Who would decide the use of nuclear weapons by NATO and would the European members be able to influence Washington's decision? As Ian Thomas has recognized, the issues were "command and control" of NATO's nuclear forces. A compromise solution had already been found with the so-called dual key arrangements for the use of intercontinental ballistic missiles; the host nations had to give their agreement to the use of these weapons. However, Britain and other European nations were concerned about whether in a sudden emergency the United States would wait for the agreement of the Europeans. After all, despite the looming threat of a global nuclear war during the Cuban missile crisis, the Americans had not bothered to consult with the Europeans; even the British had hardly been informed. Thus, the anxieties of the Europeans that they might be dragged into a nuclear confrontation with the Soviet Union against their will dominated the early to mid-1960s.
American ideas about the establishment of a multilateral force (MLF), put forth in early 1963, were a reaction to this. Although originally developed during the Eisenhower years, the Kennedy administration argued that the MLF would lead to greater alliance cooperation and transatlantic military transparency. It would create an integrated nuclear force similar to the existing integrated conventional forces and thus increase NATO military efficiency. Washington also hoped to integrate British and French nuclear forces into the MLF and thereby defuse the discussion about the creation of German-owned nuclear forces and Germany's participation in nuclear decision making.
The MLF was to consist of twenty-five ships, to be jointly owned, financed, controlled, and manned by the entire alliance; each ship would be equipped with eight Polaris missiles. In military circles it was technologically and organizationally a very controversial concept, and many experts doubted its military usefulness. However, the Kennedy administration appeared to believe that the MLF could be used to overcome the deep dissatisfaction within the alliance with regard to NATO's nuclear strategy. It would continue full American control over the deployment and use of nuclear weapons while giving the Europeans the impression that they were participating in nuclear decision making. At the same time, the MLF concept had the advantage of preventing the further proliferation of nuclear weapons within the alliance. Despite strong German support for the MLF (and strong French and British opposition; London even proposed its own equally flawed Atlantic Nuclear Force concept), by 1965 the Johnson administration had withdrawn the idea. Instead, Washington was now in favor of creating a nuclear planning group within NATO.
By then France's increasing uneasiness about American dominance of and strategy for the alliance was rapidly posing a severe threat to the unity and coherence of NATO. Paris doubted the U.S. commitment to nuclear deterrence if America's own national interest (that is, U.S. territory) was not threatened. Moreover, many in France argued that multilateral nuclear deterrence would contribute to the prevention of nuclear war. Thus, for French nuclear strategy the existence of NATO was counterproductive and not necessary at all. In addition, De Gaulle viewed American predominance in NATO and talk of an Atlantic community with ever greater suspicion. Not without justification he believed that Washington intended to prevent the development of independent nuclear forces within NATO and to keep individual alliance members as subordinate as possible.
In early March 1966 President Lyndon Johnson was informed that France would leave NATO's Integrated Military Command (IMC) and that all NATO forces and NATO headquarters had to depart France by April 1967. This led to another severe crisis within NATO, yet by late 1967 the alliance had resettled in Brussels, and no lasting damage to the unity of the remaining NATO IMC members had occurred.