James Martin Center for Nonproliferation Studies
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Research Story of the Week

New Nuclear Weapons?

By Charles D. Ferguson and Peter D. Zimmerman[1]

MINOR SCALE, a 2,400 ton high explosive test simulating a 4 kiloton near surface nuclear detonation (late 1980s). Source: www.dtra.mil

Will the United States produce newly designed nuclear weapons under the Bush Administration? Over the next couple of years, the answer will likely be "no." Recent activity, however, in Congress and the Administration has raised concern that the prospect of new U.S. nuclear weapons has increased.

On May 20, the Senate voted down by a 51-to-43 mostly party-line vote a Democratic-sponsored amendment that would have preserved the ban against pursuing research and development of low-yield nuclear weapons.[2] This amendment was attached to the $400.5 billion FY 2004 Defense Authorization bill. The Senate's vote comes as expected following the recent Senate Armed Services Committee vote to repeal the 10-year-old ban. On May 21, Senate Democrats tried to strike a compromise position that would have allowed research but continued the ban on development of these weapons. A rival amendment submitted by the Armed Services Committee Chairman, Senator John Warner, Republican of Virginia, that would require congressional approval for full-scale development work won by a 59-to-38 vote. Some Senate Democrats vowed to keep fighting moves toward new nuclear weapons.[3]

Spratt-Furse Ban on Low-Yield Nuclear Weapons

The 1993 ban known as the Spratt-Furse law states, "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." This law defined low-yield nuclear weapon as "a nuclear weapon that has a yield of less than five kilotons."[4]

Although the Spratt-Furse law appears to rule out any research and development of new low-yield nuclear weapons, this law leaves room for interpretation. In fact, the law does not explicitly state what research and development activities are prohibited or permitted. Weapons research occurs in various phases. In general, early phases of research would involve exploration of concepts for a weapon with a given proposed mission. Later phases of development would transform a conceptual design into a workable weapon. The final phase would result in actual production of the fully designed and developed weapon. Based on common Defense Department practice, national nuclear weapons laboratories would have sufficient leeway to engage in the early phases of research. Not until the relatively late phase in which development engineering takes place would Congress have to step in to determine whether to appropriate funds for continued development and production.[5] While the Administration has argued that the continuation of the Spratt-Furse ban "will hinder the ability of our scientists and engineers to explore technical options to deter national security threats of the 21st century,"[6] the law could be interpreted to allow such research as long as the laboratory work did not venture into full development and production of such a weapon.

The House of Representatives modified the Spratt-Furse law to allow research but clearly prohibited development and testing of low-yield nuclear weapons. The week prior to this vote, the House Armed Services Committee (HASC) on May 14 set the stage for this compromise. Unlike the Senate Armed Services Committee, the HASC did not completely repeal this ban. Representative Curt Weldon, Republican of Pennsylvania, and one of the co-authors of the ban Representative John Spratt, Democrat of South Carolina, formulated a compromise position that would allow research on low-yield nuclear weapons but would prohibit development, production, and acquisition of these weapons. Because of the differences in the votes in the Senate and House, a conference committee will have to resolve the positions.

High-Yield Robust Nuclear Earth Penetrator

The Administration is set to receive the $15 million it seeks for FY 2004 research on nuclear weapons for the Robust Nuclear Earth Penetrator (RNEP) project. (The House version of the legislation called for $22 million; the different amounts will be settled in a conference committee.) The RNEP project would investigate using high-yield nuclear weapons to destroy deeply buried bunkers that could contain weapons of mass destruction or enemy's command and control facilities. Amendments to cut funding for the RNEP failed in both the House and Senate. However, Senator Bill Nelson, Democrat of Florida, introduced an amendment that passed and that would require a study to determine if the RNEP technology can be applied to conventional earth-penetrating weapons. In support of Nelson's amendment, Armed Services Committee Chairman Senator John Warner, Republican of Virginia, expressed that "we should do everything possible to channel all of our scientific efforts toward not using a nuclear weapon, and this does just that."

The Administration's public intentions remain for the time being only to do research on new nuclear weapons. On May 20, Defense Secretary Donald Rumsfeld stated that the United States wants to study these weapons "not to develop, not to deploy, not to use" them.[7] A study of any type of weapon would be required as a proof of concept before the Administration can begin to seriously contemplate development or production. However, Rumsfeld prefers lifting the complete ban on both research and development. The Administration wants to have the flexibility now to possibly shift into development phases if research proves promising rather than to have to return to Congress to request permission for such development. But Congress would still have to approve any funds for actual production.

Revitalized Nuclear Weapons Complex

Increased Nuclear Testing Readiness

In addition to the Administration's plans to research low-yield nuclear weapons, the Administration is taking other steps to mobilize the U.S. nuclear weapons complex. Currently, the nuclear weapons laboratories require about three years in order to prepare for a full-scale nuclear weapons test at the Nevada Test Site. Plans are underway to cut that preparation time in half to 18 months or perhaps as low as 12 months.[8] Although the Bush Administration does not support the Comprehensive Test Ban Treaty's ratification, it does continue to maintain the testing moratorium. For the time being, an increase in test readiness does not imply that the United States will renew full scale nuclear testing. While the United States has not conducted a full nuclear test since 1992, it has performed several subcritical experiments in which no explosive nuclear chain reaction can occur, or even be closely approached. Keeping the time needed to prepare a new nuclear weapon test longer than one year is vital, because it requires at least one budget cycle in which Congress could act to disapprove such a test.

To support the revitalized posture of the nuclear weapons complex, the Administration has requested a substantial 8.2% increase in the FY 2004 budget for the Stockpile Stewardship program that maintains the safety and reliability of the U.S. nuclear arsenal. The total program's annual budget would climb to $6.378 billion.[9] This amount is greater than the Cold War peak yearly spending on nuclear testing.[10]

Plutonium Pit Production

Another revitalization step is to restart plutonium pit production. Plutonium pits are the key parts of the primary fission component of nuclear weapons. Pit production has not taken place in the United States for 14 years. Initial plans call for the capacity to make about 50 pits per year, but the Department of Energy (DOE) has proposed building a facility that could manufacture around 500 pits per year.[11] Critics of this proposal have charged that the United States has at least created the appearance of producing nuclear weapons although Administration officials have countered that the pits are intended to replenish existing pits in the current arsenal. Each year several pits of each type are destroyed during examinations to determine if any aging problems have developed; this procedure will ultimately deplete the supply of pits for some weapon systems below their currently required numbers, and new pits may be required. Addressing the issues of nuclear warhead production and nuclear testing at the May 2003 Preparatory Committee meeting for the 2005 Non-Proliferation Treaty Review Conference, the United States Mission in Geneva issued a Fact Sheet that states, the "U.S. is not developing, testing, or producing any nuclear warheads and has not done so in more than a decade." Still, the renewal of pit production could be interpreted as the production of nuclear warheads. Nevertheless, all other nuclear powers, declared and undeclared, are probably continuing to produce nuclear weapons.

Arguments for New Nuclear Weapons

Bunker Busters

The 2002 Nuclear Posture Review (NPR) discussed exploration of the "Advanced Concepts Initiative," which included the requirement for "improved earth penetrating weapons (EPWs) to counter the increased use by potential adversaries of hardened and deeply buried facilities."[12] These so-called "bunker busters" would not necessarily exclusively involve nuclear weapons. The Department of Defense (DOD) and the DOE already have been studying three options for EPWs. The two nuclear options are modifying existing nuclear weapons and developing new nuclear weapons while the third option is determining whether conventional weapons could destroy or disable deeply buried bunkers.[13]

Destroying a bunker by direct blast effect requires generating a shock wave using an explosive. Detonating an explosive inside the ground enhances the shock wave "by a factor of 10 to 20 relative to a surface burst."[14] Even with this shock enhancement, very powerful explosives are required to be able to destroy deeply buried bunkers. Although low-yield nuclear weapons are typically many hundreds of times more powerful than the most powerful conventional weapons, low-yield nuclear weapons may not be powerful enough to demolish very deeply buried bunkers. "For the shock to reach down to 1,000 feet with enough strength to destroy a hard target in dry rock, the warhead would require a yield significantly larger than 100 kilotons."[15]

In June 2000, Dr. Stephen Younger, former Associate Director for National Security at Los Alamos National Laboratory, wrote a thought-provoking paper "Nuclear Weapons in the Twenty-First Century" in which he examined scenarios for potential bunker buster use. While he noted that only a small set of the bunkers of concern are very hardened and deeply buried, those that are would "require high yield to destroy them. No application of conventional explosives or even lower-yield nuclear explosives will destroy such targets, which might include hardened structures buried beneath hundreds of feet of earth or rock. For such purposes, it might be desirable to retain a small number of higher-yield nuclear weapons in the arsenal as deterrents against enemy confidence in the survival of such targets."[16] Such weapons, with yields in the multi-megaton range, could produce extreme ground shock when the x-rays produced in the detonation blasted away the top layer of soil or rock. One example of a suitable gravity bomb is the nine megaton B53.[17]

Recognizing the limitations of low-yield nuclear weapons against these types of targets, the DOE and DOD study of the Robust Nuclear Earth Penetrator will include research into modifying existing high-yield nuclear weapons for a bunker-busting role. In fact, such modification has already occurred. In the mid-1990s, the United States wrapped a hardened bomb casing around one version of the B61 nuclear bomb. The modified weapon was designated the B61-11.

In addition to the perceived need for bunker-busting nuclear weapons, Administration officials have stated other potential reasons why research into new nuclear weapons would support U.S. security. As the 2002 NPR indicated, the Bush Administration seeks to form a "revitalized defense infrastructure that will provide new capabilities in a timely fashion to meet emerging threats." The NPR points out "several nuclear weapon options that might provide important advantages for enhancing the nation's deterrence posture." As already discussed, one of the options is to explore improvements to earth penetrating weapons. Additional options include "possible modifications to existing weapons to provide additional yield flexibility in the stockpile" and possible development of "warheads that reduce collateral damage."

The Administration may have in mind bringing back the neutron bomb. Because such an enhanced radiation weapon would generate more neutrons and less blast than typical nuclear weapons, it was thought to provide the capability of killing people inside buildings or other structures, for example, soldiers inside tanks, while minimizing the blast damage. However, even the neutron bomb could produce considerable fallout if used in a bunker-busting role.

Buttressing Deterrence

Why would these options improve deterrence? The logic is that deterrence hinges on making a credible threat. The current U.S. nuclear arsenal is primarily geared toward Cold War style deterrence in which the United States aimed to counter the large nuclear forces of the Soviet Union. Administration officials have argued that the current threat environment demands a reevaluation of the U.S. nuclear stockpile.

Presently, the U.S. nuclear arsenal contains thousands of strategic nuclear warheads for the land-based and sea-based ballistic missile forces. These warheads have relatively high-yields ranging from about 100 to 475 kilotons. In addition, the United States possesses two types of gravity nuclear bombs: the B61 and B83. Unclassified estimates peg the B83's maximum yield at 1,200 kilotons and the B61's maximum yield at 170 kilotons. The B61 and B83 may also have the capability of a dial-a-yield feature that could permit a yield as low as 0.3 kilotons.[18] For comparison, the Hiroshima bomb had a yield of about 15 kilotons. As mentioned above, the United States has already modified the B61 bomb into a bunker-busting variant known as the B61-11. Reportedly, DOE and DOD are exploring potential modifications to the B83 bomb casing in order to have available a very high-yield bunker buster.

Because there are relatively few, if any, low-yield nuclear warheads still in the U.S. arsenal, the United States may be limited in its ability to deter use of low-yield nuclear weapons by nascent nuclear states, such as North Korea, according to advocates of low-yield nuclear weapons.[19] Armed with high-yield nuclear weapons, the United States may be self-deterred from credibly threatening to use these weapons in a scenario in which another nation only has low-yield weapons in its nuclear arsenal. Under such a scenario, low-yield nuclear weapons would offer the United States a means to wage a proportionate response.

Additionally, if a nascent nuclear nation actually used a nuclear weapon against the United States or its allies, the United States would likely seek to destroy with sufficient force the remaining nuclear weapons in the other nation's arsenal while also likely striving to minimize the collateral damage done by U.S. nuclear weapons. During the Cold War, the U.S. nuclear forces were primed to launch a quick retaliatory strike against possible Soviet use of nuclear weapons. Such a rapid response was designed to target any remaining unlaunched Soviet nuclear weapons. By aiming to destroy these yet-to-be launched warheads, the United States sought to limit any further damage to its homeland. Similarly, low-yield nuclear weapons could provide the means for double damage limitation. That is, these weapons could likely ensure the prevention of further damage from other nuclear weapons used by a nascent nuclear state and could attempt to lessen the damage the United States would inflict on the nascent nuclear state.

Another argument in favor of new nuclear weapons research is that the United States needs "to understand the technological implications of nuclear weapons concepts and countermeasures tested by other states, to ensure that U.S. weapons and delivery platforms (including advanced conventional strike systems) perform effectively," according to the 2002 NPR. As argued above, the Spratt-Furse ban does not necessarily prohibit such research. Some experienced nuclear weapon designers have argued that their successors should execute some low-yield designs (not intended for development, testing, or production) as a way of learning about those weapons should a real need for them ever arise.

The Administration's strong interest in completely removing any ban on research and development of low-yield nuclear weapons raises the question of what other applications for these weapons does the Administration have in mind. Of the many possibilities, two options have received attention in the past but have probably not been fully developed.

Pure Fusion Weapons

Conceivably, the United States may want to renew research and development of pure fusion weapons. These hypothetical weapons, if possible to develop, would not need a fission primary bomb to ignite the fusion of deuterium and tritium (heavy forms of hydrogen). For many years, the United States and Russia and perhaps other nuclear weapons states have researched whether it is possible to create high enough temperatures and pressures inside a confined space to fuse together deuterium and tritium for the purposes of a developing a novel weapon.[20] Unlike these secretive military programs, the open civilian fusion research programs are well known and are not intended for nuclear weapons' development. Pure fusion weapons offer the possibility of generating a nuclear yield of very small amounts. A study several years ago expressed concern that pure fusion weapons research and development would subvert the intent of the Comprehensive Test Ban Treaty.[21] Pure fusion weapons offer the advantage of reduced collateral damage stemming from radioactive fallout because these weapons would not create the highly radioactive fission products associated with standard nuclear weapons.

Despite the many millions of dollars spent by both the Los Alamos and Lawrence Livermore National Laboratories in the years from 1952 to 1992 to produce a pure fusion weapon, no measurable success was ever achieved by either laboratory. The power densities needed to ignite a fusion reaction still seem attainable only with the aid of a fission explosion or in large reactors, such as the Sandia Z-pinch, the Livermore National Ignition Facility, or various tokamaks. Regardless of any claimed advantages of pure fusion weapons, building those weapons does not appear to be feasible.

Missile Defense

The Administration may be seeking a way to make an effective missile defense system. President George W. Bush has vowed to deploy a national missile defense system before the 2004 presidential election. In April 2002, the Chairman of the Defense Science Board openly reported that Defense Secretary Donald Rumsfeld encouraged him to investigate the use of nuclear weapons to make up for the current missile defense system's shortcomings. This announcement caused uproar on Capitol Hill in some quarters. Soon afterward, the story died or at least went underground. However, there is no firm evidence that the Administration intends to develop low-yield nuclear weapons for missile defense.

Such weapons could provide a means to allow a defense based on the present, somewhat accurate, hit-to-kill interceptor to work. A hit-to-kill missile interceptor must actually strike the incoming missile warhead. A nuclear-armed interceptor would only have to place a low-yield nuclear weapon within 10 to 100 meters of the ballistic missile warhead. Another supposed advantage of a nuclear interceptor would be that the x-ray flash from a low-yield nuclear weapon would knock out countermeasures such as decoys. Low-yield weapons in the 1- to 5-kiloton region do not produce significant electromagnetic pulses at the surface of the earth to affect operations there. They do, however, introduce high energy electrons into the earth's magnetic field, and these particles can seriously damage satellites in low earth orbit.

Understanding the Capabilities of Nuclear Terrorists

A further argument in favor of allowing U.S. designers to explore concepts for low-yield nuclear weapons is to understand the kinds of devices nuclear terrorists might be able to build. Terrorists' improved nuclear devices (INDs) would likely be similar to the first or second generation nuclear weapons built at Los Alamos during the Manhattan Project in the 1940s. The current generation of American nuclear weapons scientists is focused on maintaining the technologically sophisticated U.S. nuclear arsenal, which is far more advanced than a terrorist group's potential INDs. However, directing nuclear weapons scientists to study IND concepts would not necessarily require repeal of the Spratt-Furse ban. Neither would it be possible for U.S. scientists to explore the full range of feasible IND designs in sufficient detail to provide instructions to ordnance disposal technicians without further examination of the actual devices.

Arguments Against New Nuclear Weapons

Conventional Means of Attack Are More Feasible and Have Less Collateral Damage

Many people have raised objections against new nuclear weapons or have reasoned that conventional weapons can fulfill the military missions. Even the commander of the U.S. Strategic Command Admiral James Ellis has explained that conventional precision-guided bombs can destroy or disable deeply buried targets. To disable a deep bunker, conventional bombs could be used to block the entrances and exits to the bunker. Moreover, Special Forces, such as SEAL teams, could attack surface facilities that support bunkers.[22] In addition to these conventional tactics, Michael Levi has explored another potentially promising method termed an "information umbrella" approach. He envisions that the United States either alone or with allies could declare that no enemy vehicles would be permitted to come near the bunker and its related facilities and that "any vehicle attempting to enter or leave the facility would be destroyed."[23]

Conventional weapons would still produce far less collateral damage than nuclear weapons. First, the typical low-yield nuclear weapon of around a kiloton yield is many hundreds of times more powerful than the large-yield conventional weapons. Second, as physicist Robert Nelson showed in a study published last year, earth-penetrating weapons "cannot penetrate deeply enough to contain the nuclear explosion and will necessarily produce an especially intense and deadly radioactive fallout." He further concluded, "A one kiloton earth-penetrating 'mininuke' used in a typical third-world urban environment would spread a lethal dose of radioactive fallout over several square kilometers, resulting in tens of thousands of civilian fatalities."[24]

Hazards to Troops

U.S. troops would also risk injury or death if they tried to operate in such a radioactive environment. As Rose Gottemoeller has written, "Nuclear use would slow [military] operations, not speed them up, and the logistics would be nightmarish."[25] Military officers have also been recently expressing serious reservations about sending "their soldiers into a radioactive environment that may also contain biological and chemical agents scattered by the [nuclear] bomb."[26]

Chemical and Biological Agent Dispersal

Although proponents of nuclear bunker busters claim that such weapons are needed to neutralize chemical and biological agents in bunkers, independent studies have questioned whether nuclear weapons would be effective at chemical and biological agent neutralization and whether they would lead to dispersal of these agents. Michael May, a former director of the Lawrence Livermore National Laboratory, and Zachary Haldeman calculated that a nuclear explosion can reliably destroy buried CW and BW agents if the nuclear blast occurs relatively close to them. They also outline scenarios in which the nuclear explosion could disperse the agents.[27] In 2002, Levi obtained similar results in his study that compared nuclear versus non-nuclear options.[28] This month, the Natural Resources Defense Council also published a detailed critique of earth-penetrating and low-yield nuclear weapons.[29]

Nuclear-Tipped Ballistic Missile Interceptors

Nuclear-tipped ballistic missile interceptors have distinct advantages over both hit-to-kill missiles and fragmentation warheads. Even a small nuclear weapon is able to destroy targets over a much larger volume of space than any conventional device. This reduces the requirements for the interceptor guidance system, and also alleviates some problems with discrimination of real targets from decoys.

A nuclear interceptor used above the sensible atmosphere has only two kill mechanisms available: its x-ray flash and the neutrons from the nuclear explosion. In the absence of an atmosphere, the characteristic fireball and thermal flash are not produced. Neither is there any blast or shockwave. The x-ray flash destroys the warhead in an interesting way: the radiation is absorbed quickly in the outer skin of the warhead, causing a thin layer of structure to vaporize essentially instantaneously. This is called x-ray ablation. The vaporized material recoils from the reentry vehicle, producing an intense shock to the structure. At high enough x-ray fluences the shock is able to destroy the components (nuclear, high explosive, and electronic) of the target and may even shatter the reentry vehicle (RV). At lower fluences the radiation may simply destroy the electronics required to detonate the nuclear weapon via the mechanism of source-generated electromagnetic pulse (SGEMP).

An internal shockwave great enough to shatter the RV produces a catastrophic kill and may be unambiguously visible to ground-based radar. Destroying the electronics produces a mission kill, but is not likely to be visible to ground-based sensor systems.

The neutron flash from a nuclear interceptor is extremely unlikely to destroy the RV. It will cause a large number of fissions in the uranium or plutonium of the target, and these may kill the warhead by at least two mechanisms. If the RV is spinning, and if the neutron-induced fissions release enough energy to melt or soften the fissile material, it will be distorted so that it cannot be assembled into a supercritical mass. Neutrons can knock out secondary charged particles, and these may produce SGEMP or directly destroy the chips in the electronics. In neither case, however, will the destruction be visible to ground- or space-based fire control systems.

The ability of small nuclear weapons to destroy biological weapons in canister submunitions has been greatly exaggerated. Authoritative research at Livermore National Laboratory indicates that a one-kiloton device must burst within only a few meters of the RV in order to do the job because the canisters closest to the explosion effectively shield those farther away.

Most of the lightweight decoys which have been extensively studied are made of a thin plastic film (e.g., 1 to 2 millimeters of polyethylene) which has been aluminized to make it electrically conductive and so reflect radar waves. In addition, these decoys may be heated slightly and coated with additional thin films to give them the approximate thermal infra-red signature of real warheads. Such balloons are made of essentially the same material as is used for plastic garbage bags.

The only mechanism by which a nuclear blast can damage these decoys is x-ray ablation. Analytic studies with official Defense Nuclear Agency (now Defense Threat Reduction Agency) unclassified x-ray absorption software clearly indicate that such balloons can be made extremely hard against x-ray ablation simply by using a very thin aluminum coating, too thin to absorb significant amounts of x-ray energy, and by placing the coating on the inside.[30] The use of interior coatings greatly reduces the ability of the x-ray flash to blow off enough material to distort the shape of the decoy or to alter its course. The ablated aluminum vapor is contained within the balloon, and hence there is no rocket-like impulse imparted to the whole object. Decoys farther than about 100 meters from a one-kiloton explosion should remain essentially untouched.

More study is needed to determine the extent to which a small nuclear explosion might blind ground-based and space-based radar and space-based infra-red systems (including other interceptors) viewing the blast.

All of the handicaps suffered by low-yield nuclear weapons used to intercept ballistic missiles can be overcome by simply using warheads with yields on the order of 20 to 100 kilotons. These devices are too small to cause significant EMP at the surface of the earth, but they are large enough to inject so many high energy electrons into the existing Van Allen radiation belts that virtually all low earth orbit satellites, including imaging and some communications satellites, will be destroyed within a matter of weeks. Indeed, the radiation will remain for months or years making reconstitution of the satellite constellations difficult or impossible for an extended period.

Russian Interest in New Nuclear Weapons

During the recent congressional debate over whether to approve of research and development of new U.S. nuclear weapons, Russian President Vladimir Putin reportedly hinted that Russia might be developing new nuclear weapons. However, his statements are mired in ambiguity. The New York Times reported that he said, "I can inform you that at present the work to create new types of Russian weapons, weapons of the new generation, including those regarded by specialists as strategic weapons, is in the practical implementation stage."[31] Notably, he did not use the word "nuclear." In a separate news report, Nikolai Sokov of the Center for Nonproliferation Studies said that although Putin did not use this word, it was implied. Dr. Sokov characterized Putin's comments as "brief and Delphic."[32]

Opponents and proponents of lifting the ban on research and development of new U.S. nuclear weapons viewed Putin's remarks through their own lenses. Opponents, such as Representative Ellen Tauscher, Democrat of Walnut Creek, California, said, "There has been a degradation of our position on arms control, and it is making others nervous." In contrast, Representative Heather Wilson, Republican of New Mexico, said that Russia's purported nuclear weapons research program is "one of the reasons why we need to research advanced concepts, so we are not caught unprepared."[33]

The U.S. Department of Defense is concerned about Russian nuclear weapons research, and many inside that department allegedly believe that Russia actually wants these weapons. In contrast, other agencies, such as the U.S. State Department, are uncertain about Russia's intentions. Putin could be just trying to signal the United States to not pursue new nuclear weapons.

Implications for Nonproliferation

Even if a strong case can be made for new U.S. nuclear weapons, development and production of these weapons would undermine U.S. commitments under the nuclear Non-Proliferation Treaty (NPT). Along with the other four de jure nuclear weapons states, the United States pledged under Article VI of the NPT "to pursue negotiations in good faith on effective measures relating to the cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a Treaty on general and complete disarmament under strict and effective international control." Although this article does not specify a time-bound commitment, production of new nuclear weapons would take steps backwards from the treaty's obligations "to pursue ... nuclear disarmament."

In addition, the United States would put itself in a hypocritical position if it proceeded with nuclear weapons' development. In essence, the United States would be saying to aspiring nuclear weapons states, "Do as I say, not as I do." During the recent congressional debate, Senator Dianne Feinstein, Democrat of California, said, "To my mind, even considering the use of these weapons threatens to undermine our efforts to stop proliferation."

Complicating Presidential Decision Making

Finally, any U.S. president would face major constraints on using any type of nuclear weapon whether or not it is low-yield. Giving a president the option to use very low-yield weapons would tend to confuse rather than clarify his decision making during a crisis. Unless the United States were responding to another's use of nuclear weapons, a president would find making the decision to use nuclear weapons almost insurmountable.

Von Clausewitz's "fog and friction" of war factor could also play a role in escalating an armed conflict in which a very low-yield nuclear weapon was used. In other words, during the heat of the battle, a U.S. regional commander would probably not stop to assess the exact yield of a nuclear weapon used against the United States or its allies. He would know that a nuclear weapon was used and would likely request authority to respond with a nuclear weapon and would probably not weigh out an exact proportionate response with a nuclear weapon of an equivalent yield. This scenario could climb the escalation ladder to an even more devastating conflict.

During last year's crisis between India and Pakistan, Secretary of State Colin Powell summed up the nuclear use dilemma when he said, "[T]he thought of a nuclear conflict in the year 2002, with what that would mean with respect to the loss of life, what that would mean with respect to the condemnation -- the worldwide condemnation -- that would come down on whatever nation chose to take that course of action, would be such that I can see very little military, political, or any other kind of justification for the use of nuclear weapons. Nuclear weapons in this day and age may serve some deterrent effect, and so be it, but to think of using them as just another weapon in what might start out as a conventional conflict in this day and age seems to me to be something that no side should be contemplating."[34]

[1] Dr. Peter D. Zimmerman, a nuclear physicist, served as the Chief Scientist of the Senate Foreign Relations Committee from August 2001 to January 2003. The views expressed here are his own.
[2] Carl Hulse, "Senate Votes to Lift Ban on Producing Nuclear Arms," New York Times, May 21, 2003.
[3] Helen Dewar, "Nuclear Weapons Development Tied to Hill Approval," Washington Post, May 22, 2003, p. A5.
[4] "Prohibition on Research and Development of Low-Yield Nuclear Weapons," Section 3136, P.L. 103-160, FY94 Defense Authorization Act.
[5] David Wright, "The Spratt-Furse Law on Mini-Nuke Development," Backgrounder, Union of Concerned Scientists, May 11, 2003, provides an excellent summary of the phases of nuclear weapons research and development as well as the provision of the Spratt-Furse law.
[6] Carl Hulse, "Both Houses Back More Military Spending," New York Times, May 23, 2003.
[7] Vicki Allen, "Rumsfeld Pushes for New Nuclear Weapons Study," Reuters, May 20, 2003.
[8] House Policy Committee, Subcommittee on National Security and Foreign Affairs, "Differentiation and Defense" An Agenda for the Nuclear Weapons Program," U.S. House of Representatives, February 2003, p. 6, http://wilson.house.gov/Media/Photos/NuclearReport.pdf.
[9] Linton F. Brooks, Prepared Testimony before the Senate Committee on Appropriations Subcommittee on Energy and Water Development, April 10, 2003.
[10] Stephen Schwartz, editor, Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940, (Washington, DC: Brookings, 1998), p. 79.
[11] Yevgenia Borisova, "U.S. Restarts Its Nuclear Machine," The Moscow Times.com, April 24, 2003, http://www.themoscowtimes.com/stories/2003/04/24/001-print.html.
[12] Excerpts from the Nuclear Posture Review are available at: http://www.globalsecurity.org/wmd/library/policy/dod/npr.htm.
[13] For more on the details of these options, see Charles D. Ferguson, "Mini-Nuclear Weapons and the U.S. Nuclear Posture Review," Research Story of the Week, CNS, April 8, 2002, http://cns.miis.edu/pubs/week/020408.htm.
[14] Sidney Drell, James Goodby, Raymond Jeanloz, and Robert Peurifoy, "A Strategic Choice: New Bunker Busters Versus Nonproliferation," Arms Control Today (March 2003), http://www.armscontrol.org/act/2003_03/drelletal_mar03.asp.
[15] Ibid.
[16] Stephen M. Younger, "Nuclear Weapons in the Twenty-First Century," LAUR-00-2850, Los Alamos National Laboratory, June 27, 2000, http://www.fas.org/nuke/guide/usa/doctrine/doe/younger.htm.
[17] Thomas B. Cochran, William Arkin and Milton Hoenig, Nuclear Weapons Databook, Vol. 1: U.S. Nuclear Forces and Capabilities (Cambridge, MA: Ballinger Publishing Co., 1984), p. 58.
[18] NRDC Nuclear Notebook, "U.S. Nuclear Forces, 2002," Bulletin of the Atomic Scientists (May/June 2002).