Now that the notion of defending all of America’s cities against a massive Soviet nuclear attack had pretty much been exploded, SRI’s main business was helping the Army come up with new justifications for a large-scale ABM system. Wohlstetter had trounced the quality of SRI’s work in the late 1950s at RAND, but became intrigued with ABMs in the mid-1960s and joined their cause. Wohlstetter realized that once the Soviets made their long-range missiles more accurate, hardened shelters could no longer resist the pulverizing power of a nuclear blast and the ICBM force would once again be vulnerable. An ABM, if situated to defend the ICBM bases, could do much to relieve the peril.
Wohlstetter also worried about China. He was a strong hawk on the Vietnam War, viewed North Vietnam as a puppet of Red China and foresaw the Chinese Communists carrying out further acts of aggression against American allies in Asia over the next decade. If the U.S. could not so easily intervene with troops, we would have to offer these allies the protection of our “nuclear umbrella,” as with the NATO allies. But if the Chinese invaded an Asian ally, a nuclear threat by the U.S. might not be credible since China—once it amassed its own nuclear arsenal—could strike back against American cities. However, if the U.S. had a decent ABM system, the Chinese would know that their nuclear retaliation would inflict only minor damage, and they would thus be deterred from provoking aggression. The promise of successful coercive first-strikes against the U.S.S.R. had died out as the Soviets had built up their own arsenal; with the ABM, Wohlstetter hoped to revive the strategy against China.
The notion held not only for China, but for all “lesser” powers that might build a small arsenal of bombs and threaten to use them irresponsibly. Wohlstetter was an ardent foe of the global proliferation of nuclear weapons. It was the one issue on which he and liberal arms controllers agreed. To Wohlstetter, an ABM would discourage similar nations from engaging in nuclear blackmail and, thus, from obtaining nuclear bombs at all.
A national debate broke out over the ABM in 1968. The intellectual leadership came from an assemblage of highly distinguished scientists who had worked on nuclear weapons for many years. The debate first sparked when, in reaction to McNamara’s San Francisco speech, Hans Bethe and Richard Garwin wrote an article on ABMs in the May 1968 Scientific American. The article cited the vulnerability of the radar to blackout or to a single detonation on the ground, the effects of decoys or multiple warheads, the ability of the offense to counter the defense at lower cost. This was the first time that these points had been outlined in public, on an unclassified basis.
The debacle in Vietnam, increasingly obvious by 1968, spurred several legislators to question Pentagon policies more generally. The ABM was the most expensive weapons system up for deployment; popular protest against it was intense in those areas where the Army wished it sited; the Bethe/Garwin piece made a splash at just the right moment politically. Leading antiwar senators suddenly sought out the scientific community for advice on opposing the ABM. By the summer, John Sherman Cooper, Philip Hart and Edward M. Kennedy formed alliances with fellow Senators William Fulbright, Albert Gore, Jacob Javits, Charles Percy, Mike Mansfield, George McGovern, Frank Church, Mark Hatfield and, not least, Stuart Symington, onetime super-hawk whose views on defense had changed considerably with the impact of Vietnam. As a group they consulted Bethe, Garwin, Killian, Kistiakowsky, Wiesner, Sidney Drell, Wolfgang Panofsky, Paul Doty, Jack Ruina, George Rathjens and other scientists. Virtually all of these scientists had been members of Eisenhower’s PSAC panel in 1959 or the Pentagon’s Reentry Body Identification Group of 1958, both of which had concluded that ABMs were impractical for the reasons that Bethe and Garwin spelled out a decade later. In the spring of 1969, the scientists opposed to the ABM started to testify before congressional committees. It was a new phenomenon. Only Administration witnesses had testified on defense matters in the past.
In January 1969, Richard Nixon became President and almost instantly shifted the terms of the ABM debate. A few weeks into the Administration, Nixon’s national security adviser, Henry Kissinger, came over to the Pentagon to talk about the ABM with the new Deputy Secretary of Defense, David Packard, and a few of his aides. Explicitly speaking for the President, Kissinger laid down the orders: first, there will be an ABM; second, it will be cheaper than the Democratic Administration’s ABM; third, it will shoot down Soviet missiles, not just Chinese missiles. Packard sent the orders to John S. Foster, Jr., the Pentagon’s R&D director. Foster’s conclusion: defending cities would be impossible given the guidelines on how much to spend and who the enemy was; therefore, the ABM must be geared primarily to defending the Minuteman ICBM silos.
On March 14, Nixon announced that the Sentinel ABM, the Nike-X derivative to defend against Chinese attack, was now dropped, and that a new ABM to defend Minuteman, called Safeguard, was in. The new rhetoric proclaimed that defending cities would only prompt the other side to increase its offensive-missile force, inciting an arms race, and that the major threat now was a first-strike by the Soviet Union against the retaliatory forces of the Strategic Air Command.
The new rationale blunted the case of the critics somewhat. Defending Minuteman sites was easier than defending cities: if one missile made it through the defense, a city would be destroyed in the one case, but only an ICBM would be destroyed in the other; since an ICBM was much less valuable than a city, the defense would not have to be perfectly foolproof. Moreover, in the early phases of the ABM debate, many of the critics, including Hans Bethe, had testified that an ABM designed to defend ICBMs instead of cities might be acceptable.
However, the critics now noted that the new Safeguard ABM was physically the exact same system as the old Sentinel—meaning that all of the old problems still existed and made the system unworkable. Second, they argued that the Minuteman was not so vulnerable after all. Third, they maintained that even if the Soviets could knock out all of the ICBMs, the U.S. would still have enough warheads on board the Polaris submarines at sea and on alerted B-52 bombers to devastate the Soviet Union; thus, Minuteman vulnerability alone would not sufficiently tempt the Soviets to launch a first-strike. Fourth, they argued that even if Minuteman were vulnerable and even if the Soviets were thus provoked to launch a first-strike, Safeguard would not provide adequate defense: the radar was vulnerable, the ABMs themselves would probably not be so reliable, and there was something fishy about the official U.S. intelligence estimates of Soviet missile strength.
The big danger, as the Administration saw it, came from the U.S.S.R.’s gigantic SS-9 ICBMs, which were believed to carry a twenty-five megaton warhead. Recently, however, the Soviets had been observed testing the SS-9 with three warheads of smaller but still quite large size. There was some controversy within the intelligence community as to whether this new missile was merely a Multiple Reentry Vehicle (MRV), like the Polaris A-3 “Claw,” or whether it was a Multiple Independently targetable Re-entry Vehicle (MIRV), meaning that each warhead on board could be guided to a completely separate target. In June, the National Intelligence Estimate judged that it was merely an MRV; but under heavy pressure from Henry Kissinger and Defense Secretary Melvin Laird, the CIA changed the NIE to read that the SS-9 was probably a MIRV. Since the CIA had previously noted that the Soviets would have 420 SS-9s by the end of 1975, only if each of the three warheads were MIRVs could they threaten all 1,000 Minuteman ICBMs. Only then would there be a rationale for Safeguard.
However, the ABM critics noted that if the SS-9 were less threatening than the CIA had projected, Safeguard would be superfluous. Conversely, if the Soviets built more SS-9s than anticipated, the Safeguard program would be drenched by an attack. George Rathjens, one of the anti-ABM scientists, calculated that just a few additional months of SS-9 production would be enough to overwhelm the interceptor missiles defending the Minuteman sites and make them vulnerable again. In short, as Rathjens put it, the “defense would be effective only if the Soviet Union were to tailor its threat to match Safeguard’s limited capabilities.”