Abstract

The development of small nuclear weapons and the threat of theft associated with it would dramatically increase the likelihood of the use of nuclear weapons by states or terrorist organizations alike, despite the fact that the use of such weapons would be illegal under international law in most of the scenarios in which the use of small earth-penetrating nuclear weapons could be envisaged. Recent statements by the British Defense Secretary Geoff Hoon indicate that after the next elections the British Parliament will have to decide on whether to replace the submarine-based Trident system with such weapons. This developments will force other states to acquire small nuclear weapons as well. Since small nuclear weapons might be perceived as relatively "harmless", this might include non-nuclear powers as well. Such a new nuclear arms race would not be limited by the rationale behind the Cold War doctrine of mutually assured destruction (MAD) and also include terrorist organizations, which in the past have attempted to gain access to nuclear weapons. Given the technical need for further tests of this new kind of weapon, the Comprehensive Test Ban Treaty can become a crucial tool for addressing these dangers.

I. Introduction

Today, in this age of global terrorism, the world might be closer to nuclear tests, than it has been in years. And it are not only rogue states like Iran or North Korea which are interested in testing new nuclear weapons. Until recently it could be assumed that the states which currently possess nuclear weapons would no longer see the need for nuclear tests due to data collected in the past. But since the 1997 Project Sand Dune the U.S. Departments of Defense and Energy have studied nuclear options against hard and deeply buried targets (HDBTs).[1] The wars in Afghanistan and Iraq, in particular the Battle of Tora Bora and the attacks against Saddam Hussein's bunkers, have strengthened the position of those advocating the development of such weapons. In this article, we will examine whether the perceived need to create new, smaller,[2] nuclear weapons poses a challenge the regime of the Comprehensive Test Ban Treaty (CTBT) or whether the treaty is sufficient to avoid the tests that will be required during the development phase of such robust nuclear Earth-penetrating (RNEP) weapons.[3]

In its 1996[4] advisory opinion regarding the legality of the use of nuclear weapons and the threat thereof,[5] the I.C.J. was unable to render an opinion on small nuclear weapons, since the Court had no information under which circumstances the use of such low-yield[6] nuclear weapons was envisaged, nor whether the use of small nuclear weapons would bear the risk of an escalation of the conflict in question to an all-out nuclear war.[7] With recent developments, both of a technological as well as of a political nature, this situation has changed:

II. Background

After the Bush-Administration formulated a new Nuclear Posture Review,[8] funding for Research into the possibilities for nuclear "Bunker Buster" devices was approved by Congress on 12 November 2002.[9] Low-yield nuclear weapons are explosives with an output smaller than the one caused by 5kT[10] of TNT and their development is prohibited by a decade-old U.S. law.[11] Yet new small nuclear weapons might have yields "substantially higher than five kilotons".[12] Funding for research into the required RNEP technology which is supposed to allow for a penetration which in turn should allow for a subterranean explosion, was initially approved by the U.S. Congress in 2003.[13] One year later the U.S. Senate supported a repeal of the Spratt-Furse-Law and asked the President to get congressional approval for the development of the controversial weapons. A 9 June 2004 decision by the Congress to stop funding the project[14] indicates how controversial the issue is.
Current plans for the use of the proposed low yield nuclear devices include command bunkers at underground locations as targets. Within 700m from the point of impact death is said to be "immediate" and still some 2100m away the radioactive dose would be lethal,[15] although this seems questionable if the weapon's yield should really be above the 5kT limit.[16] Of particular concern is the fact that a subterranean explosion will blow out large amounts of radioactive dirt which inevitably will rain down over the local region, since no RNEP can bury even a 0.15kT device deep enough to contain the explosion.[17] According to tests conducted in the U.S., a 5kT device needs to be buried some 650ft while a 100kT explosion can only be contained if it occurs 1300ft under ground.[18] Yet, the preferred[19] earth-penetrating-nuclear-bomb currently available, the B61-11,[20] is only able to penetrate some 20ft into dry air when dropped from an altitude of 40,000ft.[21] Deeper penetrations required in order to reduce fallout will be extremely difficult to achieve due to the heat-induced deformation of the tip of the warhead upon impact.

III. The Legality of the Application of Low-Yield Earth Penetrating Nuclear Weapons in Armed Conflicts

But it might not only be difficult to create the envisaged new weapons. Their actual use in combat might also run counter to international law: According to Art.51(4) AP1 and customary international law (CIL) non-discriminatory attacks are prohibited. Although it is not illegal per se to use weapons which do not discriminate between military and civilian targets,[22] it is illegal to use weapons in a non-discriminatory way. While the use of RNEP weapons against ICBM-silos in remote areas might be permissible, using them against command bunkers in urban areas would most certainly constitute a violation of Art.51(4) AP1 and CIL. Furthermore prohibit Art.35(2) of the 2nd additional protocol to the Geneva Conventions (AP2) and CIL[23] the causation of unnecessary suffering or injury, which in this case would result from burn injuries. Since all weapons causing burn wounds are considered to be prohibited under this rule,[24] nuclear devices are also prohibited under Art.35(2) AP2 and CIL. This would still leave open the possibility of using RNEPs against ICBM-silos provided the operating forces are located at a sufficient distance.[25] A further prohibition of the employment of RNEPs could arise from Art.35(3) AP1, due to its environmental impact, especially since RNEPs will create more fallout than above-ground nuclear weapons.[26] The latter considerations also apply to mere tests. Given the proposed context of the use of RNEPs, the Non-Proliferation Treaty[27] (NPT),[28] specifically the obligation not to use nuclear weapons against non-nuclear powers,[29] needs to be taken into account.
Using small nuclear devices with present day RNEP technology therefore would be illegal under international law if used against targets located in populated areas and must not be used against human targets at all due to the unnecessary suffering which would be caused, both of which would violate International Humanitarian Law, specifically Art.51(4) AP1, Art.35(2) AP2 and CIL. The use of such weapons would furthermore be contrary to Art.35(3) AP1 and might violate negative security assurances given by nuclear powers under the NPT-framework.
 
IV. The Danger of Proliferation and a renewed nuclear Arms Race
 
Yet not only would the use of RNEP weapons be illegal under almost all circumstances envisioned by the supporters of such weapons, their development would also create a whole host of dangers: Smaller nuclear devices are relatively easy to transport, sell and steal, making them a target of interest for rogue states and terrorists[30] alike. The thought that terrorists might attempt to acquire and use nuclear weapons is neither far fetched nor new: in early 1977 Red-Army-Faction[31]-terrorists attacked a U.S.Army-Depot in West-Germany in a failed attempt to acquire a nuclear weapon.[32] In the wake of the 1993 terrorist attacks against the WTC the FBI feared that radioactive material was to be placed around Manhattan.[33] Two years later Bosnian Serb leader Radovan Karadzic allegedly attempted to acquire a nuclear weapon[34] and Chechen commander Shamyl Basayev told the Russian TV-station NTV that four cases of cesium had been placed in Moscow.[35] One containing 32 kg of cesium was found in Ismailovo Park.[36] Also in Moscow, a businessman was killed by g-ray emitting pellets which had been placed in his office by the local mafia.[37] Also the repeated attempts on the life of Pakistan's leader Pervez Musharraf must be seen in the context of Pakistan's nuclear capabilitites: as the Pakistani version of the al-Azma.[38]
Also other states will be interested in acquiring low yield nuclear weapons as well. According to Geoff Hoon, the next UK Parliament will have to decide on replacing the Trident[39] warheads with smaller nuclear weapons.[40] Finally, the psychological barrier regarding the use of nuclear weapons will be lowered significantly,[41] especially when taking into account the current U.S. "preemptive strike"-policy.[42] This in turn will most likely compel rogue states and terrorists to acquire nuclear capabilities of their own[43] - and to use them if threatened by nuclear attack. The deterrent effect of such weapons will be outweighed by far by the increased risk of an actual use of nuclear weapons.[44]
 
V. The Need for Further Tests of Small Earth-Penetrating Nuclear Weapons and the Role of the Comprehensive Test Ban Treaty
 
Ironically, it is the already described fact that current RNEP technology is not yet ready to be deployed to combat and the need for further tests of RNEP, i.e. tests with actual nuclear warheads, that might provide the key to preventing the further development of small nuclear weapons. Given the poor performance of the  B61-11 in earlier tests[45] new tests seem to be almost[46] inevitable.[47] This is where the CTBT comes in: According to Art.I(1) CTBT all tests resulting in nuclear explosions[48] are banned.[49] Only the CTBT can provide a sufficient legal basis for the prevention of further nuclear tests during the development of RNEP weapons and therefore play a key role in the prevention of the deployment and use of such weapons. Given the dangers inherent in the development of RNEP, especially the significantly increased danger of the use of nuclear weapons by states and terrorists alike, as well as the danger of a new nuclear arms race not limited by the reasoning behind the MAD doctrine,[50] the CTBT has now become more important than ever.

Notes
 
[1] The work undertaken so far was presented to Congress by Donald Rumsfeld in October 2001, Report to Congress on the defeat of hard and deeply buried targets, submitted by the Secretary of Defense in conjunction with the Secretary of Energy, July 2001 (submitted in October 2001), cf. also News Review, US Keeps Options Open on Low-Yield Nuclear Weapons, in: Disarmament Diplomacy, Issue No. 62, January - February 2002; Ian Hoffman, Low-Yield Nuke Bombs endorsed, in: Albuquerque Journal, 15 August 2000. 
 
[2] The last time small nuclear weapons were deployed to potential conflict areas was from 1961 - 1971 when the United States stationed several hundred "nuclear bazookas" nicknamed Davy Crockett in West Germany. 
 
[3] The basic idea behind RNEP comes from the early days of the Cold War, when the U.S. Navy deployed Mk8 a.k.a. LC (light case), nicknamed "Elsie" in 1953. "Elsie" in effect was not much more than a modified gun-type gravity bomb similar to "Little Boy", the bomb used over Hiroshima. The Mk8 was later modified and became the Mk11. Other attempts at RNEP technology followed, including the W86 warhead for Pershing II missiles, which was developed in 1980 but later abandoned due to a "change in the Pershing's targets from underground command-and-control bunkers to surface-based mobile missile launchers". Greg Mello, New bomb, no mission - the government says it is no longer building new bombs. So why is it deploying a new version of the B61 nuclear bomb ?, in: 53 Bulletin of the Atomic Scientists (1997), No. 3, pp. 28 et seq
 
[4] Not to be confused with I.C.J., Legality of  the Use by a State of Nuclear Weapons in armed Conflicts, Advisory Opinion, in: I.C.J. Reports 1996, pp. 66 et seq., in which the I.C.J. came to the conclusion that it lacked jurisdiction to give an advisory opinion, cf. ibid., para. 31.
 
[5] I.C.J., Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, in: I.C.J. Reports 1996, pp. 226 et seq.
 
[6] For an overview over nuclear weapons currently deployed by the United States, Russia, China, Great Britain, France, Pakistan, India and Israel cf. Center for Defense Information (ed.), Nuclear Issues: The World's Nuclear Arsenals, 4 February 2003.
 
[7] Ibid., para. 94.
 
[8] Christine Kucia, Congress Approves Nuclear 'Bunker Buster' Research, in: Arms Control Today, December 2002.
  
[9] Ibid.
 
[10] cf. fn. 7 and  John Burroughs, The Lawfulness of 'Low-Yield', Earth-Penetrating Nuclear Weapons.
  
[11] The so called Spratt-Furse Law is part of the Fiscal Year 1994 Defense Authorization Act (Public Law 103-160, Congressional Bills, 103rd Congress), section 3136 of which, entitled Prohibition on Research and Development of Low-Yield Nuclear Weapons, states that "(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."
 
[12] Everet Becker, as quoted by Kucia, op. cit.
 
[13] Kucia, op. cit.
 
[14] In 2003 Congress had voted in favor of the new nuclear weapons, cf. News Review, Congress Embraces New Nuclear Agenda, Opens Door Wider to 'Mini-Nukes', in: Disarmament Diplomacy, Issue No. 72, August - September 2003
 
[15] Markus Becker, Forscher entwerfen Bushs nukleare Sense, in: Spiegel Online, 11 November 2003,
 
[16] A 10 kT device causes a 99 % propability of serious injury at as little as 400 meters, cf. NATO Handbook on the medical aspects of NBC defensiv operations - AMedP-6(B) - Part I - Nuclear, no. 405. 
 
[17] Robert W. Nelson, Low-Yield Earth-Penetrating Nuclear Weapons, in: F.A.S. Public Interest Report, Journal of the Federation of American Scientists (F.A.S.), January / February 2001, pp. 1 et seq., at p. 2.
 
[18] Ibid.
 
[19] The B61-11 is often referred to as the only earth penetrating nuclear weapon available to U.S. forces. According to William M. Arkin and Robert S. Norris of the Natural Resources Defense Council (as quoted by Greg Mello, op. cit., there are approx. 750 B61-7s in the active stockpile. The B61-7 has a hardened nose and a yield that can vary from 0.3kT - 370 kT (ibid.).
 
[20] The 1,200lb B61-11 is the first nuclear weapon added to the U.S. arsenal since the end of the Cold War and was developed and deployed secretly to replace the aging 8,900lb B53 which has a yield of some 9Mt and was first deployed in 1960 but could only be delivered by B-52 bombers which are relatively vulnerable. The B61-11 is designed to be delivered by the Northrop B-2A "Spirit" Stealth Bomber and even F-16 Fighter Jets, cf. Greg Mello, ibid.
 
[21] Nelson, op. cit., at p. 4.

[22] But see also the wording in I.C.J., Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, in: I.C.J. Reports 1996, para. 78 et seq.
 
[23] Stefan Oeter, Kampfmittel und Kampfmethoden, in: Dieter Fleck (ed.), Handbuch des Humanitären Völkerrechts in bewaffneten Konflikten (1994), pp. 89 et seq., at p. 96.
 
[24] cf. William J. Fenrick, New Developments in the Law Concerning the Use of Conventional Weapons in Armed Conflict, in: 19 Canadian Yearbook of International Law (1981), pp. 229 et seq., at pp. 239 et seq. 
 
[25] Although at first sight the question might come up, in how far current International Humanitarian Law is useful for evaluating situations in which one (small) nuclear device is used to prevent e.g. the start of a ballistic nuclear missile, the problem was solved which the creation of the GBU-37 bomb, which can take out ICBM-silos, formerly thought to be vulnerable only to nuclear devices like the 9 Mt B53 gravity bomb. Deployed in 1962, the B53, which is to be carried internally by B-2 aircraft, was supposed to be replaced by the B83. Yet in 1987 the U.S. DOD decided to keep this high-yield weapon, since it was considered a necessary weapon against HDBTs (Center for Defense Information (ed.), Nuclear Weapon Database: United States Arsenal). Under START II the U.S. will likely keep some 50 B53s, cf. Robert S. Arkin / William M. Norris, Nuclear Notebook: U.S. Nuclear Weapons Stockpile, in: 52 Bulletin of the Atomic Scientist (1996), No. 4, pp. 63 et seq. 
 
[26] Sidney Dell / Raymond Jeanloz / Bob Peurifoy, Bunkers, Bombs, Radiation, in: Los Angeles Times, 17 March 2002.
 
[27] Reprinted in 7 ILM (1968) pp. 809 et seq.
 
[28] cf. I.C.J., Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, I.C.J. Reports 1996, para. 105 (2) D.
 
[29] George Bunn, The Legal Status of U.S. Negative Security Assurances to Non-Nuclear Weapon States, in: The Nonproliferation Review 1997, pp. 1 et seq. The United States declared in 1995 that it would not use nuclear weapons against non-nuclear powers, unless in case of an "invasion or other attack on the United States, its territories, its armed forces or other troops, its allies, or on a State towards [which] it has [security commitments], carried out or sustained by such a non-nuclear weapon State in association or alliance with a nuclear weapon State." (Declaration by the United States of America (1995), as quoted by Burroughs, op. cit.)
 
[30] On past terrorist attempts to acquire nuclear weapons cf. Barry L. Rothberg, Averting Armageddon: Preventing Nuclear Terrorism in the United States, in: 8 Duke Journal of International and Comparative Law (1997), pp. 79 et seq., at pp. 92 et seq.
 
[31] Rote Armee Fraktion a.k.a. Baader-Meinhof-Gang.
 
[32] Andrew & Leslie Cockburn, One Point Safe (1997), p. 61.
 
[33] Rothberg, op. cit., at pp. 110 et seq.; FBI probed Iranian nuclear attack plan, UPI, 19 Feb. 1996, available in LEXIS, News Library, UPI File.
 
[34] Rothberg, op. cit., at p. 85; Chris Hedges, An Old Tale of Swindle Resurfaces in Bosnia, in: N.Y. Times, 14 Dec. 1997, p. A5.
 
[35] Ibid., at p. 110. 
 
[36] Gavin Cameron, Nuclear Terrorism: A Real Threat ?, in: 8 Jane's Intelligence Review (1996), pp. 422 et seq., at p. 425.
 
[37] Ibid.
 
[38] On al-Azma, the crisis in the Arab world caused by the presence of U.S. forces in the Arab world and Arab muslim states being opposed to each other over the Iraqi occupation of Kuwait in the context of international terrorism cf. Yossef Bodansky, Bin Laden - The Man who declared War on America, Roseville (2001), p. 33.
 
[39] The U.S. Navy also considers trading the current Trident warheads for RNEP technology. So far, only approx. 11 % of all Trident warheads meet the Trident II D5 hard target requirements, while many U.S. Ohio Class submarines, in particular those deployed in the Pacific, are still equipped with the older Trident I C 4 missiles, which can carry only the 100kT W76 warheads in Mk4 reentry bodies, but not the 455kT W88 warhead, which makes a modification necessary. Modifing the Tridents' reentry body is important since "in the START II regime, of course, the ICBM hard-target killers are going out of the inventory and that cuts back our ability to hold hard targets at risk. The air force has some plans for how to upgrade their ICBM force to restore that capability. We can do that with the Mk4 reentry body for 10 cents on the dollar in terms of investment because of the accuracy of our system, and we have made this option available to the strategic CINC." Admiral George P. Nanos, Strategic Systems Update, in: Submarine Review, April 1997, pp. 12 et seq.
 
[40] Brian Brady, UK plans 'mini-nuke' strike force, in: Scotland on Sunday,  23 May 2004.
  
[41] This effect has been discussed before with regard to other nuclear weapons which have been perceived as "less harmful", cf. Richard A. Muller, Are kinder, gentler weapons more evil than meaner, crueler ones ?, in: Technology Review, 20 May 2003, with regard to the Neutron Bomb and the aforementioned Davy Crockett nuclear bazooka, which "reduced the nuclear threshold near to zero, and was vigorously opposed by arms control advocates" (ibid.). 
 
[42] Charles V. Peña, Mini-Nukes and Preemptive Policy: A dangerous Combination, Cato Institute Policy Analysis No. 499, 19 November 2003 (download the executive summary of this paper).
 
[43] On the potential effect of the development of "small" nuclear weapons by one state on other states cf. the comment made by Senator Dianne Feinstein when introducing, together with Edward Kennedy, legislation aimed at preserving the Spratt-Furse Law, News Review, Congress Embraces New Nuclear Agenda, Opens Door Wider to 'Mini-Nukes', op. cit., and see also Hans Bethe et al., Scientists' Letter to the Senate on Mini-Nukes, 19 May 2003.
  
[44] cf. the remarks by Joseph Biden in the Senate in support of the Feinstein-Kennedy bill, which failed, quoted in News Review, Congress Embraces New Nuclear Agenda, Opens Door Wider to 'Mini-Nukes', op. cit. 
 
[45] cf. above II.
 
[46] The only alternative to new tests is described by Stephen M. Younger of the Los Alamos National Laboratory in his paper Nuclear Weapons in the Twenty-First Century (2000), in which he envisions "simple, rugged nuclear weapons designs that might be maintained at relatively low cost and without the need for nuclear testing" (p. 19). Yet Younger also admits that some "super-hard" HDBTs (such as certain bunkers in the Russian Federation which are located underneath hundreds of meters of rock) might require larger yields to destroy them (p. 10).
 
[47] Although neither South Africa nor Israel have conducted nuclear tests, both examples are basically irrelevant with regard to RNEP weapons since South Africa and Israel appearently ahve benefitted from ealier tests undertaken elsewhere, cf. Union of Concerned Scientists (ed.), CTBT and Nonproliferation.
  
[48] Although Art.I(1) CTBT leaves room for non-explosive nuclear activities like the tests required under the U.S. Stockpile Stewardship and Management Program (SSMP) (cf. the announcement made by President William Jefferson Clinton on 11 August 1995), the fact that RNEP technology has never been fully tested, i.e. not only regarding the depth of impact but also with an actual nuclear explosion occurring underground, indicates that the measures allowed under Art.I(1) CTBT and planned under the SSMP would be insufficient in order to determine the functionality of the RNEP technology, cf. U.S. Arms Control and Disarmament Agency (ACDA) (ed.), Article-by-Article Analysis of the Comprehensive Nuclear Test-Ban Treaty, Article I - Basic Obligations.
  
[49] The phrase "or any other nuclear explosion" in Art.I(1) CTBT only refers to peaceful nuclear explosions and therefore does not provide a prohibition of nuclear warfare, cf. ACDA, op. cit.
 
[50] The threat rationale behind the development of new smaller nuclear weapons on the other hand is seems to be a one-way-street: although there might be a "new approach to deterrence" (U.S. Department of Energy, Stockpile Stewardship and Management Plan: First Annual Update, October 1997, pp. 7 et seq.), the idea of deterrence has failed with regard to large-scale suicide attacks like 9/11, this deterrence approach differs fundamentally from MAD. Under MAD both parties were assured of their own destruction if they would ever use nuclear weapons. The "new approach" not only does not serve as a potent deterrent but also requires states to use their small nuclear weapons in order to remain "credible" in the eyes of their adversaries. This in turn will lead to renewed violence and likely to nuclear terrorism.