Pentagon Revamps Nuclear Doctrine

The Department of Defense has asked Congress to abolish the Spratt–Furse provision, a nine-year-old ban on developing new nuclear weapons below 5-kiloton yields. Meanwhile, the Air Force has made a bid for more funding for a separate, new high-yield nuclear weapon to destroy deeply buried, hardened bunkers. The requests are part of the Bush administration’s 2004 budget proposal (see the story on page 30). The development of tactical nuclear weapons—high- or low-yield—and the recent mandate that the US Strategic Command take charge of the full range of warfare options for combating foreign weapons of mass destruction increase the likelihood that nuclear weapons will be used, say critics.

The US has not manufactured a new nuclear weapon since 1990. Lifting the ban is supported by the majority of Republicans in Congress, who say they want flexibility in guaranteeing US security. Most of the Democrats oppose the ban, fearing it will lead to an end of the US moratorium on nuclear testing and launch a new arms race.

Richard Garwin, senior fellow at the Council on Foreign Relations in New York, favors US ratification of the Comprehensive Test Ban Treaty (see Physics Today, March 1998, page 24 , and December 2000, page 44 ) and says, “it would be unwise in the extreme to manufacture and place such [new] weapons into the stockpile without nuclear tests. There is no need for additional types of weapons at this time.”

The repeal of the ban and need for the new air force weapon were hinted at in the Bush administration’s unclassified version of the 2002 Nuclear Posture Review. The NPR implies that nuclear weapons could be used in retaliation for attacks involving nuclear, biological, or chemical weapons; against targets able to withstand a nonnuclear attack; or “in the event of surprising military developments.”

The NPR strategy was further refined by the public version of National Security Presidential Directive 17, signed by President Bush last year. The directive implies that the US should be prepared to launch a preemptive strike, using all military options to destroy stocks of weapons of mass destruction. Both the NPR and NSPD17 imply that the US might consider breaking international law by using nuclear weapons against a non-nuclear state; such action would violate the 1970 Nuclear Nonproliferation Treaty.

Chilling effect?

The budget request states that the research ban has had a “chilling effect” on weapons research “by impeding the ability of our scientists and engineers to explore the full range of technical options…. It is prudent national security policy not to foreclose exploration of technical options that could strengthen our ability to deter, or respond to, new or emerging threats.”

Garwin strongly disagrees with this statement. The money would be better spent, he says, on a detailed and objective analysis of the effects following a nuclear weapon’s destruction of a bunker full of chemical or biological agents.

Repeal of research restrictions is not the real worry of many scientists in the arms control community; they are more concerned about future implications described in the NPR. “Generally I am not in favor of inhibitions on R&D,” says Michael May, a former director of Lawrence Liver-more National Laboratory. “We don’t know ahead of time what that R&D will lead to, and we also don’t know ahead of time what weapons will be needed.” But, he adds, “bringing the possible use of tactical nuclear weapons back into the picture is a big shift in US strategy, in my opinion, especially when coupled with a strategy of preemption.” Adds Michael Levi of the Federation of American Scientists, “Developing low-yield nuclear weapons contributes little to deterrence and could only be conceived for warfighting.”

“There is little debate,” Levi continues, “that developing our own nuclear weapons weakens our hand in diplomatic efforts to combat proliferation. The real debate is over how much it weakens us and whether the military benefits are worth the sacrifice. I don’t think they are.”

New or adapted weapons

Some 70 countries and more than 1000 known or suspected strategic bunkers are mentioned in the NPR as targets for nuclear weapons. The B61–11—currently the only nuclear weapon in the US arsenal capable of destroying hardened bunkers—has a yield between 0.3 and 340 kilotons and explodes 6 meters underground. The Robust Nuclear Earth Penetrator (RNEP) that the air force hopes to develop would penetrate 30 meters before exploding, causing shock waves that would reach bunkers more than 300 meters beneath the surface. The RNEP would be based on the B61–11, and the air force wants the yield of the new weapon to be similarly variable: An RNEP yield below 5 kilotons would allow troops to move through an area after an explosion and receive minimum radiation poisoning. Research into the RNEP low-yield option is one reason the air force has asked that the Spratt–Furse provision be repealed.

In principle, assuming the RNEP explodes in a bunker containing biological or chemical weapons, it would generate temperatures exceeding 1000°C and neutralize the agents. But independent research on nuclear bunker busters suggests otherwise. “They are not reliably effective in that use,” says May. Robert Nelson, a theoretical physicist at Princeton University who works in technical arms control and nonproliferation, says that highly radioactive fallout would be spread over several kilometers by irradiated dirt and debris thrown up from the underground explosion or that a near miss might spread the very chemical or biological weapons meant for destruction. Although the RNEP has been discussed since the early 1990s, Congress only recently approved legislation. President Bush signed that bill into law on 20 February.

Workforce issues

Of the $21 million allotted in the proposed 2004 budget for research on new nuclear weapons, $15 million will go to the RNEP. The rest of the allottment, according to the budget request, will help revitalize an essential “nuclear weapons advanced concepts effort” that is required in order to “train the next generation of nuclear weapons scientists and engineers.” The funds will also “restore a nuclear weapons enterprise able to respond rapidly and decisively to changes in the international security environment or unforeseen technical problems in the stockpile.”

Levi doesn’t buy it. “The argument relating weapons development to lab employment changes so often it’s hard to take seriously,” he says. He points out that officials from the national laboratories stress retaining skilled employees, rather than recruiting new ones.

In his testimony at a 6 March House Armed Services Committee hearing, Everet Beckner, deputy administrator of defense programs with the National Nuclear Security Administration, stated that it is not necessary to end the Spratt-Furse provision this year “in order for us to conduct the program that we have outlined in fiscal year ‘04,” but it would be prudent to do so eventually. Beckner reminded the committee that, even if the ban were lifted, Congress would still have to approve the production and deployment of any weapon developed from the research efforts. He added that RNEP research might expand beyond theoretical design work and may include a combination of component and subassembly tests and simulations that would lead to an integral flight or laboratory test or to “a subsequent decision to proceed with further development activities.” The RNEP research is scheduled to be completed by 2006.

“This new [budget] legislation does not, as I read it, mandate or urge development or production of a new low-yield nuclear weapon,” says Garwin. “But it is highly probable that it will be so interpreted by supporters of such work.”