Since 1945, there has been only one major change in our nuclear doctrine - the shift, during the Kennedy Administration, from massive retaliation to flexible response. Despite this continuity, three secretaries of defense since then have had to respond to charges that U. S. strategic nuclear doctrine had changed during their tenure. This section states clearly what our nuclear strategy is - and what it is not.
Whereas massive retaliation sought to deter any form of Soviet aggression through the threat of immediate, large-scale, nuclear attacks against military, leadership, and urban industrial targets in the Soviet Union, the key to flexible response is explicit in its name. Massive retaliation provided only two options to a president in the event of Soviet aggression - do nothing, or launch a massive attack against the Soviet Union. As the Soviets acquired a nuclear capability, including the ability to strike targets in the United States, the credibility of a deterrent based solely upon this threat declined. The new flexible response doctrine increased the number of options available to the president, and provided the capability either to respond to Soviet aggression at the level at which it was initiated, or to escalate the conflict to a higher level.
Flexible response confronts Soviet attack planners with the possibility that we may respond to a conventional attack with conventional forces, or, if these fail to defeat the aggression, with land - and/or sea - based nonstrategic nuclear weapons, or with limited or massive use of U.S. strategic nuclear weapons against targets in the Soviet homeland. Flexible response has enhanced deterrence, multiplying the uncertainties confronting the Soviet leadership, and confronting them with the threat of costs that would far out-weigh any gains that might be achieved through aggression.
Nuclear weapons are incorporated into our flexible response doctrine at two levels. On one level, U.S. non-strategic weapons - both land- and sea-based - are incorporated into U.S. and NATO planning. These weapons could be employed to degrade Soviet military operations in a particular theater, and to induce the Soviet leadership to cease its aggression through the threat of further escalation. Strategic nuclear weapon systems are also included in planning for limited strikes to provide a capability to retaliate against military installations deeper in Eastern Europe or the Soviet homeland. The incorporation of U. S. nonstrategic and strategic systems in these options provides a president with greater flexibility.
On a second level, strategic nuclear systems are incorporated into U.S. nuclear war planning to provide the president with a series of large-scale alternative responses to a massive Soviet nuclear attack. These systems also provide the backbone for our alliance commitments. Since the inception of flexible response, planning for large-scale retaliatory options has emphasized the capability to strike at Soviet military targets separately, or in combi-nation with attacks on Soviet leadership installations and/or the industrial base. The intent of these attacks is to deny the Soviet Union the ability to achieve its war aims. By providing credible responses to the various potential levels of a major Soviet attack, these options fortify deterrence. In this context, our ability to withhold attacks against particular targets - including installations in a subset of cities particularly valuable to the Soviet leadership is intended both to influence the Soviet attack planners' pre-war planning, and - in the event of war - to provide to the Soviet leadership an incentive to terminate their attacks short of an all-out exchange. Secretary McNamara's 1963 description of the rationale behind these options, during testimony before the House Armed Services Committee, remains valid today: " In talking about global nuclear war, the Soviet leaders always say that they would strike at the entire complex of our military power including government and production centers, meaning our cities. If they were to do so, we would, of course, have no alternative but to retaliate in kind. But we have no way of knowing whether they would actually do so. It would certainly be in their interest as well as ours to try to limit the terrible consequences of a nuclear exchange. By building into our forces a flexible capability, we at least eliminate the prospect that we could strike back in only one way, namely, against the entire Soviet target system including their cities. Such a prospect would give the Soviet Union no incentive to withhold attacks against our cities in a first strike. We want to give them a better alternative."
There certainly have been evolutionary adjustments to U.S. nuclear planning since 1963. For example, the massive buildup of Soviet strategic nuclear forces, changes to the Soviet target base, and a better understanding of Soviet strategy and war aims led to shifts in the targeting of U.S. nuclear weapons systems. Deployment of more accurate weapon systems; improvements to the capability, survivability, and endurance of our command, control, and communications systems; and upgrades to our nuclear planning system also have facilitated the construction of more selective and limited options. All of these modifications, however, have taken place in an evolutionary manner, within the framework of our flexible response doctrine, not as a series of different strategies imposed by each administration. In returning to the original term-flexible response - our intent has been to emphasize the continuity of our approach to this element of our defense strategy. Yet after more than 25 years of continuity, several myths have developed regarding U.S. nuclear policy. The following discussion is intended to dispel these myths and clarify our nuclear policy aims.
Myth 1: U.S. Nuclear Strategy is Based on Mutual Assured Destruction.
Many critics have alleged that flexible response is simply massive retaliation by another name. In their view, the United States would respond to any Soviet nuclear attack with an immediate, massive strike against the Soviet homeland, including its cities. Some even believe that the U.S. response should be directed solely against Soviet cities and population, and that this was at one time U.S. policy. But this mutual assured destruction philosophy has never been U.S. policy. As noted, for over a generation we have looked for ways to develop multiple options as a means of enhancing deterrence, increasing flexibility, and controlling escalation. As early as 1963 Secretary McNamara emphasized the importance of multiple options in U.S. nuclear planning. He noted that "we have to build and maintain a second strike force that has sufficient flexibility to permit a choice of strategies.
Secretary James Schlesinger, in his FY 1975 Report to the Congress, reaffirmed the importance of strategic force flexibility, noting that "If anything, the need for options other than suicide or surrender, and other than escalation to all-out nuclear war, is more important for us today than it was in 1960.... The Soviet Union now has the capability in its missile forces to undertake selective attacks against targets other than cities. This poses for us an obligation, if we are to ensure the credibility of our strategic deterrent, to be certain that we have a comparable capability in our strategic systems and in our targeting doctrine, and to be certain that the U.S.S.R. has no misunderstanding on this point. . . . "
In his FY 1982 Report to the Congress, Secretary Harold Brown again reaffirmed the importance of selective and limited options, observing that "Our planning must provide a continuum of options, ranging from small numbers of strategic and/or theater nuclear weapons aimed at narrowly defined targets, to employment of large portions of our nuclear forces against a broad spectrum of targets."
The capability to respond in an across the-board manner has always been one of the components of U.S. nuclear strategy planned under flexible response. Indeed, that capability to inflict unacceptable damage on the Soviets' military, leadership, and industrial infrastructure may be the key deterrent to a massive Soviet attack. Deterrence, however, may fail on less than a massive scale. The importance of this fact was noted by Secretary Weinberger when he discussed what would happen if deterrence failed: "If that were to occur we cannot predict the nature of a Soviet nuclear strike, nor assure with any certainty that what may have started out as a limited Soviet attack would remain confined at that level. Nevertheless, we must plan for flexibility in our forces and in our response options so that there is a possibility of reestablishing deterrence at the lowest possible level of violence, and avoiding further escalation."
The declining credibility of a single massive response as the sole deter-rent to less than all-out aggression was recognized even in 1961, when we still had significant nuclear superiority. In fact, that recognition played a significant part in the shift to flexible response. Indeed, the key element which has, from the outset, differentiated flexible response from massive retaliation is the provision for options apart from an all-out response.
Myth 2: U.S. Strategy is Based on "Nuclear War Fighting."
Many of those who believe mistakenly that U.S. nuclear strategy was once based on MAD have also criticized the U.S. government for "shifting" from this strategy. They contend that we have adopted a nuclear warfighting strategy. These critics seem to believe that our mere possession of nuclear weapons is sufficient to deter Soviet aggression. In their view, if deterrence ever fails, the inevitable outcome will be a spasm nuclear war immediately involving massive attacks on cities. According to this philosophy, developing plans and acquiring capabilities for more selective employment options undermines stability and deterrence, and suggests our intention to fight a "limited" and/or "protracted" nuclear war.
If a limited nuclear warfighting capability is one in which a single or small number of nuclear weapons are used in an attempt to end a major conventional war before it escalates to all-out nuclear war, then, in fact, we do possess such a capability. If a protracted nuclear warfighting capability is one in which nuclear forces and their supporting command and control structure might be available and effectively employed for more than 30 minutes following the onset of a Soviet nuclear attack, then we also possess this capa-bility. The critical question is: Do these capabilities strengthen our ability to deter? The answer is "yes." It is not our intention to fight a nuclear war of any description: "limited" or "massive," "prompt" or "protracted." It is our policy to prevent nuclear war. In doing so, we must determine what would deter the Soviet leadership from considering aggression - not what would deter us. In that regard, we have watched the steady buildup of Soviet strategic nuclear forces for over two decades, and the Soviet leadership's preparations for nuclear war, along with evidence that reflects their belief that such a war may, under certain circumstances, be fought and won. That evidence includes:
The Soviets' capability to reload many of their ICBM silos after launch of the first ICBM; a capability supported by spare ICBMs and reloading exercises.
Their continued expansion of a nationwide network of over 1,500 buried command bunkers for the Communist Party and military leadership, plus an extensive mobile command system-both supported by an extensive communications network.
Increasing Soviet deployments of mobile ICBMs-the SS-24 and SS-25-which, with their greater survivability, could be employed over an ex-tended period.
The Soviets clearly can conduct both limited and protracted nuclear attacks. We must deter them from these types of aggression. Indeed, we must make a Soviet victory, as seen through Soviet eyes and measured by Soviet standards, impossible across the broad range of scenarios the Kremlin leadership might consider. We may not agree with the assumptions upon which Soviet strategy appears to be founded, but we must design a deterrent strategy that takes these factors into account to remove any temptation for the Soviet leadership to believe they could fight and win a nuclear war. Our forces and our flexible response doctrine are designed to maximize the uncertainties that Soviet leaders would face, and confront them with an unfavorable outcome in any contingency in which they may contemplate aggression.
Myth 3: As Part of its Nuclear Strategy, the U. S. Relies on a Launch-Under-Attack Policy.
Over the past decade, as Soviet ICBM counter-silo capabilities improved, some have questioned the continued survivability of the ICBM leg of the Triad. Rather than abandon one leg of the Triad, however, successive administrations chose to modernize the ICBM force by deploying the Peace-keeper ICBM in a survivable basing mode. In 1986, we decided to deploy Peacekeeper in a highly survivable rail-based system. Predictably, many of the critics who question the continued value of the ICBM force began to assert that no truly survivable basing mode could be established. They contend, therefore, that the United States has shifted to a launch-under-attack posture, since our ICBMs would be destroyed unless launched prior to the impact of the incoming Soviet attack.
As noted, successive administrations have devoted considerable effort and resources to increasing the flexibility and the number of choices available to the president should deterrence fail and the use of nuclear weapons become necessary. Asserting that the United States maintains a launch-under-attack policy ignores these efforts, and the deterrent provided by the Triad. We have not spent billions of dollars to modernize and increase the capabilities of the bomber and sea-based legs of the Triad only to leave the president with a single effective option with which to respond to a massive Soviet attack. We do not, however, intend to reduce the uncertainties facing Soviet attack planners - or the Soviet leadership. In order to increase the uncertainties in the minds of Soviet planners, it is not our policy to explain in detail how we would respond to a Soviet missile attack. However, the United States does not rely on its capability for launch on-warning or launch-under-attack to ensure the credibility of its deterrent. At the same time, our ability to carry out such options complicates Soviet assessments of war outcomes and enhances deterrence.