Why MIRV?

The Stimson Center will publish a collection of five essays in May titled, The Lure and Pitfalls of MIRVs: From the First to the Second Nuclear Age. Our authors look back at US and Soviet compulsions, and forward to how extensive MIRV programs might be in China, India, and Pakistan. The good news is that MIRVs will assuredly be far less of a factor during the second nuclear age than the first. The bad news is that MIRVing has begun in China, after a three-decades-long hiatus, and might well occur in India and Pakistan as well. More bad news: The action-reaction syndrome hasn’t been swept into the dustbin of history. Even modest MIRV programs will further complicate the triangular nuclear competition among China, India and Pakistan.

The extent of MIRVing depends on the motivations driving it. The motivations in the United States and the Soviet Union were powerful — hence the extent of MIRVing during the first nuclear age. To help edit this book and write the introductory chapter, I’ve been delving into my shoeboxes filled with 4X6 cards for evocative quotes. No US debates over arms control were as high-octane and informed as those over MIRVs (and ballistic missiles defenses, which were being teed up at the same time).

The Founding Fathers of strategic arms control went toe to toe with the Big Thinkers of nuclear deterrence. Heavyweights from the Nixon Administration faced off against their predecessors in the Kennedy and Johnson Administrations. Powerful senators – legends whose shoes have never been filled – built cases pro and con through exhaustive hearings. These senators – Fulbright, Jackson, Gore (pere, not fils), Symington, Muskie, Stennis, Brooke, et al. – engaged in informed floor debates over hugely consequential amendments. The American public was paying attention. Lobbying campaigns were in fifth gear. It was an amazing time.

These debates, as my file cards indicate, didn’t lend themselves to crystal-clear answers about the motivations behind MIRVs. Advocates offered up many reasons to see which ones would have maximal effect. Arguments shifted over time, and some of the debaters contradicted themselves. Reflections made after MIRVs were unconstrained by the 1972 SALT I Interim Agreement were in some cases too convenient to fit the facts. I’ll come to them after reviewing the five main arguments to pursue MIRVs.

A sixth argument, based on domestic politics, wasn’t offered in hearings or floor debate, but was ever-present. Nixon and Kissinger complained bitterly about harassment from Doves, but they were even more bothered by the prospect of harsh critiques from Hawks. They knew that to forego MIRVs would result in firestorms in the Pentagon and on Capitol Hill. For the pungent flavor of internal calculations, check out Vol. XXXII of Foreign Relations of the United States, “SALT I, 1969-1972.” As for the five main public arguments for letting MIRVs run free in SALT I, let’s parse them, one by one.

Negotiating Leverage

In testimony before the House Armed Services Committee on US Military Posture in 1969, the Pentagon’s Director of Defense Research and Engineering, Dr. John S. Foster, Jr., argued:

“If we find through arms control talks or by following Soviet deployments over an extended period, that they are not trying to protect their cities against us, then our hedge, the MIRV, could become the subject of proper negotiations.”

Foster, who was the Pentagon’s point person in these debates, also made this argument that the effect of MIRVs “will be to help the US position in the SALT talks” during Congressional testimony. (“ABM, MIRV, SALT and the Nuclear Arms Race,” 1970).

National Security Adviser Henry Kissinger strained to make an arms-control rationale for MIRVs in follow-on negotiations while testifying on behalf of the SALT accords on June 15, 1972:

“By setting a limit to ABM defenses the treaty not only eliminated one area of potentially dangerous defensive competition, but it reduces the incentive for continuing deployment of offensive systems… Beyond a certain level of sufficiency, differences in numbers are therefore not conclusive… Therefore, too, if we can move into the second phase of SALT, into an explicit recognition that both sides will stay away from counterforce strategies… then perhaps the premium on MIRVs will be reduced because… MIRVs were developed at first as a hedge against ABM.”

The U.S. chief negotiator during SALT I, Gerard Smith, did not find MIRVs helpful to the negotiating process. Instead, his memoir, Doubletalk (1985), recounts a complicated, well choreographed dance to allow MIRVs to run free:

“At Vienna, an ingenious and disingenuous MIRV mismatch was proposed by the two sides. The American approach would have banned deployments of MIRVs but permitted the United States, with MIRVs fully tested before a treaty was signed, to continue to produce and stockpile them… The Soviet proposal called for an unverifiable ban on MIRV production and deployment but would allow them to test MIRVs. Cynics might suspect sub rosa cooperation between two parties unwilling to give up MIRVs but anxious to appear to be in favor of outlawing them.”

Penetrating Soviet Missile Defenses

Here’s Dr. Foster again, in House Armed Services Committee testimony in 1969:

“We have to hedge against the installation of a Galosh or improved ABM around a number of cities. Also, we are still concerned about the capabilities of the Tallinn system. That system employs a number of interceptors which would be converted to an ABM capability in addition to their anti-aircraft role.”

Oddly, Secretary of Defense James Schlesinger testified before the Senate Foreign Relations Committee on March 4, 1974, that the entire rationale for MIRVs hinged on Soviet ABMs:

Senator Stuart Symington: Why do we need MIRV in the absence of ABM deployment on the part of the Soviet Union?

Secretary Schlesinger: We do not.

Senator Symington: We do not need it?

Secretary Schlesinger: We do not. We would not deploy it in the absence of ABM. The reason for doing R & D on MIRV is to prepare against the contingency that they might decide to break the treaty. We would then have the means of penetrating ABM defenses. It is our belief that, if they know we can penetrate such defenses, any desire they may have to upset the treaty will be further reduced.

Verification Difficulties in Monitoring a MIRV Ban

Opponents of a ban on MIRVs argued that the U.S. couldn’t know for sure whether the heaviest Soviet missile, the SS-9, might have already been flight-tested with MIRVs instead of with three unguided re-entry vehicles, or MRVs. And even if Soviet tests were forerunners of MIRVs, but not actual MIRVs (which was, indeed, the case), proponents argued that this Rubicon had already been crossed. As Dr. Foster testified before the House Foreign Affairs Committee (“Diplomatic and Strategic Impact of Multiple Warhead Missiles,” 1969),

“We must consider the possibility that the SS-9 triplet might be deployed on the basis of further extensive ground tests and without further flight tests.”

Secretary of Defense Melvin Laird added to this obfuscation in his testimony during the SALT I hearings in 1972:

“I have never gotten into the semantics of whether the MRV they have tested had an independent capability. I don’t think there is any sense in getting into that discussion.”

The Soviet Challenge

When asked about the choice of a MIRVed or an un-MIRVed world in Senate Foreign Relations Committee Hearings (“Arms Control Implications of the Current Defense Budget,” 1971), David Packard, the Deputy Secretary of Defense, argued, quixotically,“I do not see that it would make any significant difference.” This answer only makes sense if one presumed that the Soviet challenge was immutable.

The Senate’s Permanent Investigating Subcommittee, whose most influential member was the redoubtable Henry M. “Scoop” Jackson, advanced a similar argument in its 1968 report, “Investigation of the Preparedness Program”:

“If this [MIRVs] is within our technological capability and our resources, then prudence surely dictates that we assume that it is also within the technological capability and resources of the Soviets.”

Senator Jackson was the strongest opponent of floor amendments that tried to close the barn door on MIRVs after the SALT I accords were negotiated, arguing in 1972 that,

“The Soviets start out with 50% more launchers and 400% more throw weight, so if they proceed with an aggressive MIRV program… they can gain a lead that we could not diminish because we have a much, much smaller base.”

Targeting Requirements

Secretary of Defense Robert McNamara removed the veil of secrecy from MIRVs in an interview published in Life Magazine in September 1967. He offered several rationales, including cost-effectiveness and the ability to “overcome the most powerful defenses the Soviet could build.” “More important,” McNamara added, “we’re capitalizing on a major new technological advance.”

“We can now equip our boosters with many warheads, each of which can be aimed at a separate target… We believe that we have a substantial lead over the Soviets in this important technology. Through the use of MIRVs, we will redesign our strategic force to increase the total number of warheads. This will do two things: exhaust their defenses and at the same time better match the size of weapons to the targets to be destroyed. The net result will be an increase in military effectiveness with some reduction in the total megatons of our force.”

Albert Wohlstetter stressed this rationale in his testimony before the Senate Armed Services Committee in 1969:

“Contrary to the popular belief, MIRVs are not a reaction to ABM. MRVs (multiple re-entry vehicles) not independently aimed are a counter to ABM. MIRVs are a reaction to dispersed, vulnerable targets… It has to do with cases where a dispersed target system presented excessively tempting targets, if you could divide your payload.”

Ron Tammen’s book, MIRV and the Arms Race (1973), reaches a similar conclusion:

“The MIRV concept for Minuteman was formulated in 1962-3 as an economical means of increasing target coverage of the ballistic missile force.”

Of these rationales, which were the biggest drivers behind the US decision to MIRV? To be continued.