The twin developments of thermonuclear weapons and long-range missiles ushered in a new phase of nuclear deterrence. Now, thermonu-clear warheads hundreds or even thousands of times more powerful than atomic bombs could be attached to missiles capable of reaching other continents and destroying cities in minutes. In these circumstances, deterrence became not just a policy imperative but a necessity for the survival of the human race. It was clear that a new stage had been reached not only in the history of international affairs, but also in the history of humankind. J. Robert Oppenheimer famously likened the situation to "two scorpions in a bottle, each capable of killing the other, but only at the risk of his own life." In delivering a comprehensive evaluation of British and NATO nuclear forces to the British House of Commons in March 1955, Prime Minister Winston Churchill observed that a paradox was likely to define international affairs in the future: "After a certain point has been passed it may be said, 'The worse things get the better.' … Then it may well be that we shall by a process of sublime irony have reached a stage in this story where safety will be the sturdy child of terror, and survival the twin brother of annihilation." Begun by technological innovation, the thermonuclear revolution aroused the most basic human fears and instincts.
In view of the apparently intensifying communist threat, and particularly in light of the recent development of Soviet atomic power, Truman in late January 1950 ordered a reexamination of U.S. strategic policy. Secretary of State Dean Acheson delegated the task to the new director of the State Department's Policy Planning Staff, Paul Nitze. The result, a document known as NSC 68, was a lengthy and dramatic call to arms. Before long, the report concluded, the Soviet Union would have the capability to launch a surprise atomic attack on the United States. To deter such an attack, NSC 68 recommended a massive buildup in conventional and atomic forces and that, moreover, the United States should commit resources to developing a new type of weapon, a "super" bomb harnessing the power generated by fusing hydrogen atoms rather than splitting them. Preliminary research into such a weapon had been undertaken within the Manhattan Project by a team of scientists headed by physicist Edward Teller. But with no hope of immediate success and with military budgets shrinking in the postwar economic environment, the research was halted. Based on theoretical data, Teller predicted that a hydrogen bomb would be several hundred times more powerful than the Hiroshima bomb and capable of devastating an area hundreds of square miles, with radiation traveling much farther. NSC 68 now proposed to resume H-bomb research at a greatly accelerated rate. After heated debate over the feasibility and morality of such a weapon, Truman ordered the project to proceed.
At the height of the debate about whether to proceed with the H-bomb project, communist North Korea launched an attack on pro-Western South Korea on 25 June 1950. Truman reacted by committing U.S. troops under the auspices of the United Nations. Since the deterrent had clearly lapsed or failed, General Douglas MacArthur, commander of UN forces in the theater, and General Curtis Le May, head of SAC, both recommended revitalizing it by using atomic weapons against Communist China. Truman, however, refused to expand the war and committed the United States to a limited conflict with limited objectives, a novel mission for American military forces.
For both political parties, Korea confirmed beyond a doubt that communist forces were on the offensive and that existing U.S. strategy was inadequate to stop them. The Democratic administration reacted by embracing NSC 68 and the massive military buildup it entailed, including the development of the H-bomb. For Republicans, Korea seemed to provide ample evidence for their charge that the Truman administration's approach to national security policy was based too heavily on reaction rather than prevention and therefore was putting the United States on track for financial bankruptcy. They argued that the primary failure lay not in the logistical difficulties of projecting U.S. military force to the distant shores of the Korean Peninsula, but in the administration's failure to prevent the war in the first place. The debate reached a crescendo in the presidential election campaign of 1952, as General Dwight D. Eisenhower, the Republican candidate, and his foreign policy adviser, John Foster Dulles, launched a sustained political attack on the Truman administration's foreign policy record.
Eisenhower and Dulles promised to take a new look at American national security policy and formulate a better plan for what was clearly going to be a long struggle with the Soviet Union. Dulles declared that the United States could not afford to keep fighting expensive "brushfire" wars like Korea and that what was required instead was an economically sustainable military posture designed to deter communist aggression over the long term. Since the United States could not in all likelihood compete with the Soviet Union in amassing conventional forces, Eisenhower and Dulles contended that the best use of American resources would be to invest in the next generation of nuclear weaponry and declare the intention to react to communist aggression "where it hurts, by means of our choosing." To illustrate Eisenhower's proposed deterrent strategy to the voters, Dulles called on the analogy of municipal police forces: "We do not station armed guards at every house to stop aggressors—that would be economic suicide—but we deter potential aggressors by making it probable that if they aggress, they will lose in punishment more than they can gain by aggression." Massive retaliation, as Eisenhower's deterrent strategy came to be called, was designed to impose upon would-be aggressors a blunt choice: either to desist, or to persist with the risk of nuclear annihilation. The primary challenge for U.S. policymakers, therefore, was to make the other side believe that aggression carried a high risk of nuclear retaliation. To that end, Dulles declared that the administration would be prepared to engage in diplomatic "brinkmanship," a diplomatic policy some observers likened to the youthful, and often deadly, test of nerves known as "chicken." Eisenhower and Dulles argued that only by being ready to push the crisis to a point where the opponent backed down first would the United States be able to protect its interests. And in order to give communist leaders reason to pause, Eisenhower employed calculated ambiguity in responding to the question of whether a nuclear response would be automatic.
Once in office, Eisenhower and Dulles were confronted with the challenge of implementing the results of their promised New Look. Some of it was clearly impractical, even dangerous. Campaign promises of the political "liberation" of Eastern Europe were quickly abandoned after the June 1953 uprisings in East Germany. The deter-rence strategy proved somewhat easier, although perhaps even more dangerous. Increasing the relative emphasis on nuclear technology as opposed to maintaining large standing conventional forces allowed the administration to cut defense expenditures by about 25 percent compared to the late Truman years, leading Secretary of Defense Charles Wilson to declare proudly that the Pentagon now had "more bang for the buck."
Having adopted massive retaliation as a long-term Cold War strategy, Eisenhower and Dulles found that strategy tested in the short term by a series of crises. Nevertheless, Eisenhower threatened massive retaliation in times of crisis sparingly and deliberately. In a series of confrontations with Communist China ranging from bringing an end to the Korean War in 1953 to the Taiwan Straits crisis of 1958, Eisenhower several times threatened nuclear attack. The primary focus of U.S. foreign policy, however, remained Europe. The struggle for Germany continued to manifest itself in crises over Berlin, which in turn presented U.S. deterrence strategies with perhaps their most serious test. Given the superior strength of Soviet conventional forces in Europe and the location of West Berlin deep inside communist territory, that city was militarily indefensible. The situation was, as Senate Foreign Relations Committee chairman J. William Ful-bright put it, "a strategic nightmare." The only viable option available to the United States short of thermonuclear war was to deter the Soviets from moving against the city.
Simultaneous to these crises, the strategic balance was in a state of flux, which in turn affected thinking about deterrence. Although the Soviets had successfully tested their first atomic device as early as 1949, thoughtful observers recognized that one successful test did not make a deployable arsenal. By 1955, however, Soviet scientists had largely overcome the initial four-year lag and, particularly in the field of thermonuclear weapons, was on a par with the West. The Soviets still lagged far behind the United States both in quantity and quality of nuclear weapons, but the former's strategic arsenal was more than adequate to inflict considerable damage on the West and to play its own deterrent role. Furthermore, the accelerating arms race made it clear that the gap was narrowing. On 3 October 1952, Great Britain detonated its first atomic device on islands off the coast of Australia. Only weeks later, on 31 October, the United States detonated its first thermonuclear weapon. Less than a year after that, on 12 August 1953, the Soviet Union completed its first successful detonation of a thermonuclear device. In 1956 the first American tactical nuclear weapons were deployed in Europe. These new weapons, designed for battlefield use in localized action, came in the form of army artillery shells, each with explosive power roughly equivalent to the Hiroshima bomb.
This rapidly accelerating arms race confronted defense planners with a new question: How much was enough to deter? During the Eisenhower administration two main schools of thought defined the debate. The first held that the U.S. stockpile should consist of just enough weapons to play a deterrent role, a concept that became known as minimum deterrence. The opposing school of thought held that the United States should maintain a large and constantly growing nuclear arsenal in order to be able to engage in redundant targeting, or allocating several weapons to each target. Known as "overkill," it was this approach of building up an over-whelming nuclear force that prevailed, largely as a result of unchecked bureaucratic politics. As a result, for the remainder of the decade, the Eisenhower administration invested deeply in building up the U.S. nuclear stockpile.
On 3 August 1957 the successful Soviet test of a new type of missile, with the potential capability of reaching the continental United States from a launch-point in the USSR, augured in a new phase of deterrence. This was dramatically confirmed two months later, on 4 October 1957, when Soviet Strategic Rocket Forces used the same type of intercontinental ballistic missile (ICBM) to propel the world's first artificial satellite into space. That satellite, known as Sputnik, was in itself harmless, being little more than a nitrogen-filled aluminum sphere fitted with a rudimentary transmitter that emitted a distinctive "beep" every few seconds, but it would nevertheless have profound ramifications. For the world public, it offered a dramatic demonstration that suggested Soviet missile technology was ahead of the West's, especially when contrasted with a spate of well-publicized American test failures. The American public's fears were manifested in accusations that the Eisenhower administration had allowed first a "bomber gap" and then a "missile gap" to develop. In reality, neither gap existed, but the administration's critics made considerable political mileage of the issue. For deterrence theorists and practitioners, Sputnik also demonstrated that the mainland United States was for the first time vulnerable to direct missile attack, potentially opening a window of vulnerability that introduced new challenges to the viability of massive retaliation as a deterrent strategy. In response to Sputnik, the American government put new emphasis on missile technology and the space race. By the late 1950s U.S. intermediate-range ballistic missiles (IRBMs) and medium-range ballistic missiles (MRBMs) were based in Turkey and Italy, aimed at targets in the Soviet Union. In 1959 the first generation of American ICBMs, Atlas D missiles with a range of 7,500 miles, were deployed in California. The following year the Polaris submarine-launched ballistic missiles (SLBMs), the final leg of what became known as the U.S. nuclear triad, were added to the U.S. arsenal to complement the strategic bomber and missile forces. By the early 1960s the Corona intelligence satellite program was sending back its first photographs of Soviet military installations, promising a quantum leap in the collection of military intelligence. Meanwhile, development continued of the massive Saturn V rockets that, by the end of the 1960s, would finally shatter any concept of safety in geography by propelling Americans to the moon.
Once again, technological developments introduced new challenges for deterrence strategy. Since missiles reduced to minutes the time available to respond to a nuclear strike, then conceivably the side that struck first would have an advantage if it could neutralize the enemy's retaliatory capability in that strike. Accordingly, the Eisenhower administration implemented new procedures to protect its retaliatory capability. Beginning in 1952, SAC's primary strike forces were on twenty-four-hour alert to guard against surprise attack and so-called fail-safe procedures had been implemented. In highly classified Chrome Dome missions, B-52 Stratofortress bombers flew to within striking distance of enemy targets and waited for a signal to proceed. If no signal came, the planes returned to base. The procedures were designed partly to improve the response time of the nuclear strike force, but more importantly to ensure that the strike force could not be destroyed in Soviet first-strike attacks on airfields. Scattered and airborne, the strike force was less vulnerable. The same principle was also applied to command and control procedures. To reduce the risk that a Soviet first strike on a few central underground command centers might disable the entire U.S. nuclear strike force—possibly an incentive for a Soviet preemptive first strike—a fleet of air force planes were specially outfitted with command and communications equipment to be able to take control of the American nuclear arsenal in the event the central underground command center was destroyed or disabled. From 3 February 1961 through 24 July 1990, a Looking Glass plane was in the air at all times. Protected by mobility, these Looking Glass missions, along with the Chrome Dome missions, became key elements of the U.S. deterrent in the missile age by protecting America's second-strike capability.