The law was adopted as part of the FY94 Defense Authorization Act (Section 3136 of P.L.103-160), and was a response to interest among some in the Pentagon and policy community in developing low-yield nuclear weapons and developing roles for them in the U.S. post-Cold War arsenal.

Efforts to repeal the law emerged in 2002. In the House, Rep. Weldon (R-PA) proposed removing the prohibition, but agreed to a Rep. Spratt (D-SC) amendment on the floor that allowed research and development, but no "metal-bending." The Bush administration took no position. The Senate took no action (maintaining the law) and, in conference, the Senate prevailed.

This year, the administration asked to have the prohibition removed, and Congress is again expected to try and comply.

In recent testimony before Congress, Dr. Everet Becker, deputy administrator for defense programs at the Defense Department's National Nuclear Security Administration, stated that the repeal was not necessary for work planned through FY04.¹  He later clarified that he supported lifting the restriction, but repeated that it was not required for current planned work in the 2004 budget.

What Does the Spratt-Furse Law Actually Ban?

The law does not state explicitly what nuclear weapons activities are permitted or prohibited. However, based on the standard development phases of nuclear weapons, one can draw a distinction between early stages of research and development work on low-yield nuclear weapons (which would be permitted) and the later stages of development needed to turn a conceptual design into a fully engineered weapon ready for production (which would not be permitted).

In particular, Phase 1 (Weapons Concept Definition Study) and Phase 2 (Feasibility Study) are not oriented toward production. However, when development passes into Phase 2A (Design Definition and Cost Study) and Phase 3 (Development Engineering), this is the point at which development becomes reoriented from conceptual design work to steps required to create an actual design for production. A Phase 2A study "identifies information on costs, production schedules, options, and trade-offs, including those involving safety, security, survivability, and control features for the weapon,"² which is relevant to beginning production of the weapon. Phase 3 is traditionally the stage at which Congress is asked to appropriate substantial funds for the engineering and testing work required to begin production of a warhead for the stockpile.

In the case of modifications to an existing weapon rather than development of a new weapon, the corresponding phases are 6.2A and 6.3. As a result, the law is clearly intended to prohibit activities at and beyond Phases 2A or 3 and 6.2A or 6.3. There is ongoing discussion about whether or not Phases 2A and 6.2A should be permitted or prohibited.

In either case, it is clear that the law offers the weapons labs considerable latitude in the type of work that can be done while preventing those steps that specifically focus on production. The law does not restrict in any way the ability of the weapons labs to research and assess the feasibility of advanced weapons concepts, or to conduct design work on new weapons until that work becomes specifically oriented toward production of the warhead.

The law further increases this latitude by offering three exceptions to the restrictions. The first exception, which allows "testing devices," has been made irrelevant by the Comprehensive Test Ban Treaty. Had the treaty contained a low-yield threshold, this exception would have allowed the weapons labs to use low-yield nuclear explosions to assess weapons effects. The other exceptions are "to modify an existing weapon for the purposes of addressing safety and reliability concerns" and "to address proliferation concerns."

Arguments For and Against Maintaining the Law

The Bush administration's Nuclear Posture Review and September 2002 National Security Strategy show a clear interest in expanding the role of nuclear weapons in U.S. military policy, including their preemptive use. To allow the development of low-yield nuclear weapons, the administration has asked Congress to repeal the Spratt-Furse law in the FY04 Defense Authorization Bill. The Department of Defense (DOD) argues that the law undercuts efforts to develop new nuclear weapons and hinders efforts to revitalize the U.S. nuclear weapons labs, and that repealing it would have little effect on U.S. decisions to develop such weapons.³  We consider these three arguments below.

(1) New Weapons Development
The Defense Department argues that the Spratt-Furse ban impedes exploration of nuclear weapons concepts that were called for by the Bush Nuclear Posture Review, which "could offer greater capabilities for precision, earth penetration (to hold at risk deeply buried and hardened bunkers), defeat of chemical and biological agents, and reduced collateral damage."

As discussed above, the ban does not prohibit the exploration of nuclear weapons concepts—it prohibits moving into later phases of development that are oriented toward production of a particular weapon design.

Moreover, there are compelling reasons not to produce weapons of the type called for in the Nuclear Posture Review:

Precision targeting/low collateral damage: Increasing accuracy does not require developing new nuclear weapons. However, higher-precision targeting means that a smaller-yield weapon can be used to destroy a given target. Advocates for low-yield weapons argue there are potential military uses that require nuclear weapons, and that weapons with yields well below that of current U.S. strategic weapons would result in less collateral damage, so the United States would not be self-deterred from using them. As a result, they argue that these weapons would be more usable on the battlefield and for preemption, and that threats of use would have a greater deterrent value than high-yield weapons.

However, even low-yield nuclear weapons are very powerful and destructive. The nuclear weapon that destroyed Hiroshima had a yield of 10-15 kilotons, so weapons of up to five kilotons are still quite large. Moreover, the United States should be working to increase the barriers to any country using a nuclear weapon, especially as more countries seek or acquire the capability to build nuclear weapons. Instead, U.S. pursuit of these weapons encourages other countries to acquire them and plan ways to use them. Not only is the spread of nuclear weapons dangerous, but the acquisition of these weapons by other countries greatly increases their military strength relative to the United States.

Earth penetrators for attacking hardened underground facilities: Earth-penetrating nuclear weapons (EPW) transfer more of their energy into ground shock by penetrating into the ground before exploding, and are therefore relatively more effective at destroying buried targets than above-ground explosions of the same yield. Advocates suggest that low-yield earth penetrators could be effective at destroying hardened underground facilities while causing minimal collateral damage from fallout.

However, the distance a nuclear warhead can penetrate into the ground is small—roughly 10 meters for penetration into rock or concrete. This fact has two important consequences. First, it means that even low-yield explosions will not be contained underground; instead, the blast will create a crater and eject large amounts of radioactive debris into the air (even a one kiloton weapon would have to penetrate 60 meters for the explosion to be contained.) As a result, EPWs can cause significant collateral damage. Second, since the warhead will explode near the surface of the ground, it means that low-yield weapons will not be powerful enough to destroy deep, hardened targets such as bunkers. Instead, penetrators for this purpose require high-yield warheads. Indeed, one nuclear weapon reportedly under consideration to be used as an earth penetrator, the B83, is the largest weapon in the U.S. arsenal, with a reported yield of one to two megatons. Using a high-yield penetrator would dig a very large crater and create enormous amounts of fallout.

Moreover, the United States has conventional penetrators that can be used to attack near-surface features of underground facilities, such as communications equipment, etc.⁴

Defeat of chemical and biological weapons: A recent argument that has been advanced for low-yield nuclear weapons is that they can be used to destroy chemical or biological weapons agents that might be stockpiled above or below ground, using the tremendous heat and radiation released by nuclear weapons.

However, recent studies have shown that the heat and radiation produced by a nuclear weapon will only destroy chemical and biological agents in a relatively small area around the explosion.⁵  Moreover, how effective the destruction is depends on how the agents are stored, how much soil or other material is between the agent and the explosion, etc. As a result, there is considerable uncertainty about how effective the destruction of these agents would be even if the location of the bunker containing the agents were known precisely. Moreover, agents that are not destroyed by the explosion may be dispersed by the blast effects of the weapon. As a result, using a nuclear weapon for this mission is likely to spread both radioactivity and chemical or biological agents over a large area.

(2) Strengthening U.S. Weapons Labs
The Defense Department argues that the United States needs a "revitalized nuclear weapons advanced concepts effort" to train the next generation of nuclear weapons scientists and engineers, and to ensure that weapons labs can "respond rapidly and decisively to changes in the international security environment or unforeseen technical problems in the stockpile." The Pentagon states that the law "has had a 'chilling effect' on this effort by impeding the ability of our scientists and engineers to explore the full range of technical options."

However, the Spratt-Furse law does not prohibit or impede weapons labs from exploring any nuclear weapons concepts, and it only prohibits moving into later phases of development in the case of low-yield weapons. Weapons designers can be trained on aspects of those later phases using designs of higher-yield weapons, if that is a concern. Should "unforeseen technical problems in the stockpile" emerge, Congress would certainly act to allow the labs to address them, but the Pentagon makes no case that a restriction on developing low-yield weapons is relevant to addressing such problems.

If the Defense Department believes that ambiguity in the scope of the ban has made weapons scientists timid in pursuing early research and development work and that this is having severe consequences, then Congress could easily clarify the language of the law.

(3) Repealing the Ban Doesn’t Matter Anyway
DOD argues that repeal of the ban does not commit the United States to developing, producing, and deploying new, low-yield warheads, since Congress must authorize and appropriate substantial funds to do so.

While this is certainly true, a push by the U.S. administration and a decision by Congress to overturn a ban that has existed for a decade would send a strong signal about U.S. intentions with respect to nuclear weapons. This is especially true in the context of other changes in U.S. nuclear policy under the Bush administration, and a stated interest in exploring low-yield nuclear weapons for attacking battlefield targets.

The perception that the United States is pursuing these weapons and contemplating nuclear missions around the globe would undermine U.S. nonproliferation efforts by giving legitimacy to the development of similar weapons by other countries. For example, Russia reportedly has an interest in low-yield nuclear weapons to compensate for its weakened conventional forces. Moreover, this perception could greatly increase the motivation of countries concerned about being on the U.S. target list to develop nuclear weapons as a deterrent.

Notes

1.  Strategic Forces Subcommittee, House Armed Services Committee, 6 March 2003.

2.  Department of Defense Instruction 5030.55 (25 January 2001), p.12.

3.   A DOD document giving its reasons for supporting efforts to repeal the ban was read into the record at the 6 March 2003 House Armed Services Committee Strategic Subcommittee Hearing.

4. See, for example, Michael Levi, "Fire In The Hole: Nuclear and Non-Nuclear Options For Counterproliferation," available at http://www.ceip.org/files/Publications/wp31.asp?from=pubdate

5.   Michael May and Zachary Haldeman, "Effectiveness of Nuclear Weapons Against Buried Biological Agents Targets," March 2003, available at http://cisac.stanford.edu/research/inprogress/mayhaldeman.html; and Rob Nelson, Council on Foreign Relations, personal communication, April 2003.
 

FY94 Defense Authorization Act

SEC. 3136
PROHIBITION ON RESEARCH AND DEVELOPMENT OF LOW-YIELD NUCLEAR WEAPONS

(a) UNITED STATES POLICY—It shall be the policy of the United States not to conduct research and development which could lead to the production by the United States of a new low-yield nuclear weapon, including a precision low-yield warhead.
(b) LIMITATION—The Secretary of Energy may not conduct, or provide for the conduct of research and development which could lead to the production by the United States of a low-yield nuclear weapon which, as of the date of the enactment of this Act, has not entered production.
(c) EFFECT ON OTHER RESEARCH AND DEVELOPMENT—Nothing in this section shall prohibit the Secretary of Energy from conducting, or providing for the conduct of, research and development necessary—
   (1) to design a testing device that has a yield of less than five    kilotons;
   (2) to modify an existing weapon for the purposes of addressing safety and reliability concerns; or
   (3) to address proliferation concerns.
(d) DEFINITION—In this section, "low-yield nuclear weapon" means a nuclear weapon that has a yield of less than five kilotons.