advance, and then the burden either of defeat or escalation would shift to Moscow. Instead of the bluster of Massive Retaliation, the new approach in Flexible Response tried to convince the Soviets that escalation would happen practically by default. Nuclear use would no longer have to result from courageous or stoic American decisions, but would instead be driven by Soviet actions.
Flexible response relied on presenting the Kremlin with a paradox, in which the success of Warsaw Pact conventional forces on the battlefield would increase the chance that nuclear weapons would be used against them. Accordingly, U.S. nuclear weapons were intentionally placed in forward positions where they would be overrun by advancing Eastern forces. Henceforth, the Soviets would know that if war broke out in Europe, NATO commanders would be cornered, through no fault of their own, into having to use their nuclear arms or lose them once overwhelmed. Soviet leaders, at least in theory, would be presented with a storyline they could understand and believe, in which the first Soviet bullet fired in Europe would inexorably be tied to the last U.S. or British missile launched from the last silo or submarine. The Soviets would therefore understand that war would likely lead to consequences that neither side wanted but that neither could escape if a crisis were to spin out of control.
NATO’s explicit rejection of “no first use,” the pledge not to initiate the release of nuclear weapons, was central to this strategy. Logically, a promise not to escalate to nuclear force had to be rejected as a matter of doctrinal first principles: if the Soviet Union truly intended to menace Europe, NATO thinkers reasoned, a “no first use” pledge would be an open invitation to Moscow to try to keep the conflict at the conventional level, where the Soviet advantage was greatest. Instead, NATO’s adoption of Flexible Response hammered home the point that the Americans and their allies were ready to drag the Soviets, rung by rung, up the escalatory ladder. A conventional war risked a battlefield nuclear war, and the tactical use of nuclear weapons risked theater nuclear war. At that point, the sunk costs of millions dead, the imminence of defeat, the panic of mass destruction, and the fog of war would all combine to make general nuclear war seem plausible and perhaps even probable. With Flexible Response, NATO was hoping to convince the leaders of the Kremlin that no matter how many men in the Red Army or missiles in the silos of the Strategic Rocket Forces, a war in Europe could not be won and to embark on such a mad enterprise would gain nothing while risking everything.
Parity and the Advent of Mutual Assured Destruction
In the mid-1960s, the Soviets began a major military buildup, including rapid increases in their nuclear forces.22 By the end of the decade, the USSR would catch up to the Americans in strategic nuclear power, creating a situation of approximate nuclear equality, or “parity.” While somewhat unequal in the numbers and distribution of their forces, by any standard each side now controlled roughly as much nuclear firepower as the other, and each could surely destroy the other under any circumstances. (Later in the decade, American secretaries of defense James Schlesinger and Harold Brown would use other terms such as “essential equivalence,” but the idea was the same.) The mathematics of parity were unarguable, but the politics were less clear: what did it mean now that East and West were so closely matched?
In concrete terms, little had changed since the early 1960s. Nuclear war still meant appalling levels of damage to both sides, with no hope of anything like a meaningful “victory” for either East or West when it was over. The arrival of Soviet-American parity represented the crossing of a psychological borderline more than a change in the military balance, since it was achieved at numbers of weapons so high that any asymmetries were functionally meaningless. For many American strategists, parity meant the end of any further toying with the pretense of fighting, much less “winning,” a nuclear war.
In fact, McNamara and his deputies in President Lyndon Johnson’s administration had already decided by the late 1960s to take what they saw as a more direct and stabilizing approach, and to discard the question of victory entirely. Instead, the Americans sought to stress to the Soviets the unavoidable and permanent damage that both sides could do to each other. The Americans proposed, in effect, to enter into a mutual hostage arrangement with the Soviet Union, where each side would forego defenses, cap limits on strategic arms, and do their best to avoid all-out nuclear war. Any indication that either side felt it could survive a nuclear war, such as civil defense programs, would be considered provocative. Likewise, there would be no attempts to hide the size and readiness of retaliatory forces. The more each side understood about the reliability of the other’s deterrent, the better. The Americans hoped that the Soviets would internalize and institutionalize the central fact of the superpower confrontations in the 1950s and 1960s that culminated in the Cuban scare: every crisis carried the risk of the extinction of both combatants.
The Soviets were not persuaded, or at least pretended they were not persuaded. The flinty Soviet marshals conceded only that victory, at best, would be defined not by a final crushing of the enemy such as the glorious Soviet entry into Berlin, but instead by the eventual long-term recovery of one system more rapidly than the other and the subsequent domination over whatever was left of the world. This position—echoed at times by some American politicians—remained the official Soviet line throughout the 1970s.23 In both private and public diplomacy, however, Moscow acted with considerably more circumspection than its rhetoric might have suggested. In 1981, Soviet leader Leonid Brezhnev finally referred to the idea of nuclear victory as “dangerous madness,” which was a hopeful sign. Later revelations, however, showed that Brezhnev’s comments were actually part of an ongoing civil-military struggle at the highest levels of the Soviet regime over the issue of nuclear war.24 Whether the Kremlin’s high command really believed the USSR could win a nuclear war can never truly be known. It might have been a bluff to intimidate the Americans (who had more than a few generals and strategists with similar views themselves), or it may have represented an inability to think beyond the parallels with World War II that dominated Soviet military writings.25
Most American analysts were far less sanguine than the Soviet brass about the outcome of World War III, and believed that both sides would be destroyed in any sizable nuclear exchange. Initially, this new doctrine was called “assured destruction,” and finally, by the wry acronym that its founders believed best described it: “MAD,” or mutual assured destruction. Although MAD seemed like a simple idea in which the victim and the attacker both perish, it was actually far more complicated. Even its various proponents did not fully agree on what it meant, and there were competing notions of MAD during the Cold War that were not fully consistent with each other. Some accepted the possibility of limited nuclear use, while the most pristine version assumed that nuclear war inevitably meant total war and subsequent annihilation. In the end, however, even the Soviets had to bow to the reality that MAD itself was a fact rather than a policy, in the sense that the ability of both sides to destroy each other was empirically undeniable.26
More arguable is what that fact meant for actual policy. Proponents of MAD argued that to ignore the reality of mutual destruction was like trying to ignore the weather, which is always present and always the same for everyone. Opponents of MAD—many of them among the civilian and military national security elites both in the United States and USSR—rejected the helplessness and passivity implied in a doctrine of mutual destruction. They argued that even if MAD was a fact, it was self-defeating to admit it, and they rejected the idea of explicitly accepting a dangerous and delicately balanced nuclear standoff as at best counterintuitive, if not flatly ridiculous.27
As far as McNamara and the MAD advocates were concerned, Soviet and American arsenals had reached such staggering levels of quantity and destructive quality that mutual destruction was inescapable. The American public, however, was understandably skeptical about a strategy whose most prominent feature was to leave the United States open to attack. MAD, at least to some critics, sounded like a retreat in the face of the new and improved Soviet nuclear arsenal. Some of those critics were members of Congress, and McNamara consequently found himself having to reassure concerned legislators on Capitol Hill that the United States could still kill most of the Soviet population if necessary. “I think we could all agree,” he said in testimony before the Senate in early 1967, “that if [the Soviets] struck first we are going to target our weapons against their society and destroy 120 million of them.”28