Depleted Uranium Weapons and International Law

Alyn Ware

[Published in Metal of Dishonor: Depleted Uranium, International Action Center, New York, 1997]

The real objective must be the abolition of war . . . In the meantime it is possible to achieve prohibitions on certain practices or weapons which routinely violate the laws of war, including DU weapons.

When the king fights with his foes in battle, let him not strike with weapons concealed in wood, nor with such as are barbed, poisoned, or the points of which are blazing with fire. (Seventh book of the legendary Hindu lawyer, Manu.)

For most of history there has been a battle between those who would justify the use of war as a necessary political tool, and those who would classify war as a crime of mass murder which must be abolished. Up until the twentieth century, war may have been opposed by the masses, but was seen by powerful rulers as politics by other means. However the devastation of the European wars and the two world wars moved even those in power to see the inhumanity of war and consider the possibility of prohibiting it.

The Hague Peace Conferences of 1899 and 1907 and the formation of the League of Nations and the United Nations had the abolition of war in mind, but failed to deliver due to the vested interests in continuing to use force and to the strongly held notion that force may be necessary in self-defense. What they could agree to, however, was that certain acts of war are “inhumane” and not necessary for the purpose of defeating the enemy. They therefore agreed to prohibit such acts. Other initiatives, such as the work of the International Committee of the Red Cross, have added to the list of proscribed actions.

What has emerged, therefore, is the development of a body of international law termed the humanitarian laws of warfare, which prohibit certain “inhumane” acts during wartime while not prohibiting the inhumane act of war itself. Such law was seriously debated during the recent International Court of Justice advisory opinion on the legality of the threat or use of nuclear weapons. The ICJ concluded that the threat or use of nuclear weapons would generally be contrary to the rules of international law applicable in armed conflict, and in particular the principles and rules of humanitarian law.1The question that arises, therefore, is whether the use of depleted uranium (DU) in weapons systems violates this body of law, and if so whether the law can be used to effectively constrain or prohibit such use.

Humanitarian Laws of Warfare

A general principle of humanitarianism in warfighting has been accepted, even if not universally adhered to, by many cultures and nations throughout the world, including some of the most warlike. Hugo Grotius, sometimes called the “father” of the laws of warfare, notes that prohibitions against inhumane methods of fighting existed in both the ancient Roman and Greek armies.2 Similar prohibitions are found in the Koran.3 The Lateran Council of 1139 prohibited the use of crossbows calling such use “hateful to God and unfit for Christians.”4

The codification5 of such principles into legal instruments began in the United States with the promulgation by U.S. President Abraham Lincoln in 1863 of “Instructions for the Government of Armies of the United States in the Field,” written by Francis Lieber and commonly known as the “Lieber Code.”6 The first codification of such principles into an international agreement occurred in 1868 with the Declaration of St. Petersburg. This legal instrument intended to “reconcile the necessities of war with the laws of humanity.”

Subsequent agreements, including the Hague Conventions of 1899 and 1907, the Geneva Conventions of 1925 and 1949, the Nuremberg Charter of 1945, and the Tribunal for the former Yugoslavia,7 have affirmed that the following acts are prohibited under international law:

i. use of weapons or tactics which cause unnecessary or aggravated devastation or suffering;
ii. use of weapons or tactics which cause indiscriminate harm, i.e. to noncombatants;
iii. use of weapons or tactics which violate the neutral jurisdiction of nonparticipating states;
iv. use of asphyxiating, poisonous or other gas, and all analogous substances including bacteriological methods of war;
v. use of weapons or tactics which cause widespread, long- term and severe damage to the environment.

These principles are accepted by most states, including the U.S., the major user of DU weapons. The U.S., for example, has affirmed these principles in the U.S. Army Manual, The Law of Land Warfare (1956). More recently the U.S., UK, France and Russia affirmed their acceptance of these principles in their statements to the International Court of Justice in the advisory opinion on the legality of the threat or use of nuclear weapons.8

Application of Laws of Warfare to Specific Weapons—the Nuclear Example

A number of States, including the U.S., hold the view that whatever is not specifically prohibited in international law is permitted. Specific prohibitions include conventions or customary law accepted by States. Thus, the U.S. accepts that the use of chemical and biological weapons are now prohibited according to the biological weapons convention9 and the Geneva Gas Protocol (1925). However, the U.S. says that nuclear weapons, which have arguably even greater destructive effects than biological and chemical weapons, are not prohibited. “The use of explosive ‘atomic weapons,’ whether by air, sea or land forces, cannot as such be regarded as violative of international law in the absence of any customary rule of international law or international convention restricting their employment.”10

The majority of States, however, believe that the application of the laws of war to specific weapons could indeed prohibit any use even if there is no specific prohibition of that weapon by convention. The most obvious example is that of nuclear weapons. A United Nations resolution adopted repeatedly since 1961 states that any use of nuclear weapons “would exceed even the scope of war and cause indiscriminate suffering and destruction to mankind and civilization and, as such, is contrary to the rules of international law and to the laws of humanity.”11

The Hague Conventions of 1899 and 1907, which codified much of the customary laws of warfare and specifically prohibited expanding (“dum-dum”) bullets and asphyxiating gases, also included a provision which stated that “[I]n cases not included in the Regulations adopted by them, the inhabitants and the belligerents remain under the protection and the rule of the principles of the law of nations, as they result from the usages established among civilized peoples, from the laws of humanity, and the dictates of the public conscience.”

This provision, known as the Martens Clause, is an integral part of the body of international law. It was most recently reaffirmed in the Geneva Convention Additional Protocol of 1977. The Martens Clause confirms that the laws of war apply to weapons and methods of warfare not specifically mentioned, and therefore could prohibit the use of certain weapons even if there is no specific convention prohibiting such weapons. The drafters of the Hague Conventions apparently understood that the advance of technology could easily lead to the development of weapons which would be at least as inhumane as expanding bullets or as non-discriminatory as poison. The International Court of Justice referred to the Martens Clause in reaching its conclusion that the threat or use of nuclear weapons is generally contrary to humanitarian laws, even in the absence of a specific convention prohibiting their use.

The Court’s conclusion makes clear that the prohibition of certain weapons under humanitarian law rests on the effects these weapons would have and the humanitarian principles which their use would violate. Thus, if a new weapon causes indiscriminate or unnecessary suffering, its use is illegal even if there is no specific mention of it in existing conventions such as the Geneva or Hague Conventions, or if it had not been invented at the time these conventions were adopted. The laws of war therefore have direct applicability for DU weapons and may provide a basis for their prohibition.

Would DU Weapons Violate International Law?

The use of DU weapons creates aggravated suffering. DU particles, when ingested by military personnel, are known to create health problems which can persist over long periods of the individuals’ lives, if not for the remainder of their lives.12 However, the difficulty with this argument is that the users of the DU weapons may insist that there are situations when there is no alternative to DU use in order to achieve the military objective, and that such suffering is therefore necessary. The fact that there is no militarily useable metal as hard as uranium could support the User’s argument.

The prohibition against indiscriminate harm is perhaps more applicable as it cannot be derogated by military necessity. DU shells spread DU over vast areas with the DU remaining potentially lethal for thousands of years. Whilst the initial impact of the DU weapon may be contained within the targeted area, the spread of DIJ after impact cannot be so contained. Upon impact a high velocity projectile of uranium metal partially burns up and generates huge numbers of micrometer-size particles of uranium oxide. Like dust, they can be carried great distances by the wind.13 Protected civilians, even if some distance from the target, are thus threatened.

In addition the offspring of military personnel who ingest DU from weapons can also be affected.14 Offspring are noncombatants, and the indiscriminate harm that DU would cause them would thus be contrary to humanitarian principles.
One problem with the indiscriminate harm argument is that any States accept that some damage to civilians may occur as part of “collateral damage” when military facilities and personnel are targeted. In order for the indiscriminate harm argument to be shown to prohibit DU weapons, disproportionate damage to civilians in relation to the military purpose would need to be proven.

The fact that the spread of DU through wind and water systems would not be able to be contained could violate the laws protecting neutral states. DU users would no doubt argue that such spread of DU to neutral states is unintentional and therefore not prohibited. The principal international treaty regarding neutrality, the 1907 Hague Convention V Respecting the Rights and Duties of Neutral Powers and Persons in Case of War on Land, does not discuss unintentional violations of neutrality, but neither does it specifically say that violations of neutrality must be intentional.

Christopher Weeramantry, a judge on the International Court of Justice, says that if the consequences of an action are known beforehand, one cannot claim unintentionality for these consequences, nor avoid responsibility for them. It is not to the point that such results are not directly intended, but are ‘by-products’ or ‘collateral damage.’... The author of the act causing these consequences cannot in any coherent legal system avoid legal responsibility for causing them any more than a man careering in a motor vehicle at a hundred and fifty kilometers per hour through a crowded market street can avoid responsibility for the resulting deaths on the grounds that he did not intend to kill the particular persons who died.15

The International Court of Justice addressed this issue in its advisory opinion on the legality of the threat or use of nuclear weapons by affirming the statement of Nauru: It is clear, however, that the principle of neutrality applies with equal force to transborder incursions of armed forces and to the transborder damage caused to a neutral State by the use of a weapon in a belligerent State.16 Even so, the ICJ did not determine that the probability of transborder damage to neutral States by the use nuclear weapons would be sufficient in every circumstance to affirm the illegality of every use of nuclear weapons on this basis. Thus, while some uses of DU weapons may be deemed illegal due to transborder damage, it is not clear that this would be true in all cases. Basing a general prohibition of DU weapons on the threat of transborder damage would therefore be difficult.

The law against use of poison or “poisoned weapons” in war would appear at first glance to provide a clearer prohibition against DU weapons. DU is clearly a poisoned weapon, the effects of which could easily be more devastating to human health than other poisons prohibited in war. Unfortunately, this prohibition received a setback when the International Court of Justice (ICJ) interpreted it to cover weapons whose prime, or even exclusive, effect is to poison or asphyxiate.17

DU weapons’ prime purpose is not to poison but to penetrate hard armor. The Court’s interpretation on this matter was soundly opposed in dissenting opinions by judges Weeramantry and Koroma, who maintained that the poisonous effects of nuclear weapons in almost all cases would be more devastating than poisons expressly prohibited. Weeramantry notes that “It [radiation] poisons, indeed in a more insidious way than poison gas, for its effects include the transmission of genetic disorders for generations.”18

Even if the Court’s excessively restrictive interpretation provides a temporary setback, it is quite possible that the more consistent interpretations of Koroma and Weeramantry will eventually become the norm. It could be argued that the use of DU weapons could cause widespread, long-term and severe damage to the environment. On the down side, the ICJ determined that the prohibition against environmental damage must be considered with respect to military necessity and proportionality (i.e., whether the military action is proportional to the precedent provocation). The ICJ stated therefore that it could not on environmental protection grounds condemn every use of nuclear weapons outright. It would be difficult to claim that the use of DU weapons has a greater environmental effect than any use of nuclear weapons.

On the positive side however, environmental law is one of the fastest growing areas of international law, with the development of provisions such as the precautionary principle and intergenerational equity which could apply to DU weapons. The precautionary principle, which is making its way into international environmental law, provides that when there is reason to believe a particular practice could generate transborder environmental damage, the onus is on the practicing party to prove its safety.

Intergenerational equity holds that subsequent generations should not be threatened by current practices. Use of DU weapons threatens particularly the latter of these principles, in that the radiation released affects subsequent generations both in terms of genetic damage to offspring, and the extremely long periods over which the uranium is radioactive.

Public conscience has been a vital component in determining the illegality of certain weapons. Citizens, mindful of the Martens Clause in the Hague Conventions, gathered 4 million “Declarations of Public Conscience” in support of the International Court of Justice case against nuclear weapons. This, along with the sixty-million strong Hiroshima and Nagasaki Appeal, the millions who marched against nuclear weapons in New York, London, Bonn and other major cities in the 1980s, the thousands of nuclear weapon free cities and the thousands of anti-nuclear groups which were established worldwide, demonstrated to the ICJ judges that there really was a strength of public sentiment against such weapons. A similar public condemnation against DU weapons would help considerably in establishing their illegality.

In conclusion it would seem that there are grounds for claiming that the use of DU weapons violates existing international law. While those grounds may not yet be strong enough in the current international climate to have such illegality affirmed through international bodies such as the United Nations General Assembly or the International Court of Justice, such law could be strengthened particularly through increasing public condemnation of DU weapons.

This is not to say however that legal action could not currently be taken against specific uses of DU weapons in order to get redress for health effects resulting from such use if such use was deemed to be negligent, nor that DU weapons could not be prohibited by means other than the existing laws of warfare.

Using the Law

The fact that DU weapons would violate the fundamental principles of international humanitarian law can be used as a motivating factor in the campaign to oppose such weapons. Citing violations of the law is another way to add to the moral outrage of citizens in order to motivate them into action. The laws of warfare are a way of opposing the erroneous belief that in war “anything goes,” and that it is therefore impossible to oppose any weapons system.

Achieving International Prohibition

The real objective must be the abolition of war, the very practice of which is inhumane and should be affirmed as illegal. Such a prohibition is however likely to be some time off. In the meantime it is possible to achieve prohibitions on certain practices or weapons which routinely violate the laws of war, including DU weapons.

Unilateral proscriptions against DU use are unlikely to be adopted as very few countries will want to have armor and shells which are inferior to and can be beaten by DU weapons of opposing armies. Governments and militaries may, however, be persuaded to abandon DU if they can be assured that everyone else is also doing so. This would need an international agreement, most likely with verification and compliance measures. A proposal for such an agreement has not yet appeared on the international disarmament agenda of the United Nations or any of the DU-using states.

However, it may be possible for anti-DU campaigners to piggyback onto the anti-nuclear weapons campaign, by seeking to incorporate DU into the international nuclear weapons abolition treaty which is likely to be negotiated within the next ten years.

Abolition 2000, the international network of organizations which is campaigning for the conclusion of such a treaty by the year 2000, has drafted a model Nuclear Weapons Convention (NWC), which proposes to include radiological weapons and DU weapons in its list of weapons to be abolished. The verification and enforcement mechanisms set up by the NWC would be sufficient to also verify a prohibition on DU weapons, thus removing the problem of having to establish a separate, costly system.

Ultimately however it will be governments which decide whether or not to prohibit DU weapons whether as part of a NWC or according to a separate agreement. Anti-DU activists need to build up the same sort of global pressure for suvh a ban as has been done for the anti-nuclear weapons campaign. Until then, the militaries which are using DU will continue to use what they see as one of the best materials to harden weapons.


1 Advisory Opinion of the International Court of Justice on the legality of the threat or use of nuclear weapons. ICJ General List No. 95, July 8, 1996, p. 36.
2 Hugo Grotius, Dc Jure Belli Ac Pads (1625) as cited in Weiss, Weston, Falk and Mendlovitz “Draft Memorial in Support of the Application by the World Health Organization for an Advisory Opinion by the International Court of Justice on the Legality of the Use of Nuclear Weapons Under International Law, Including the W.H.O. Constitution,” Transnational Law and Contemporary Problems, Vol. 4, Number 2, FaIl 1994.
3 E. Meyrowitz, Prohibition of Nuclear Weapons: The Relevance of International Law, Transnational Publishers (1990), p. 209 n.2.
4 Weiss, Weston, Falk and Mendlovitz, op. cit., p.739.
5 Codification means writing such customary law into a treaty.
6 Wells, Donald, The Laws of Warfare: A Guide to the U.S. Army Manuals, Greenwood Press (1992) p. 1.
7 Statute of the International Tribunal for the Prosecution of Persons Responsible for Serious Violations of International Humanitarian Law Committed in the Territory of the Former Yugoslavia since 1991.
8 Statements made by France (November 1, 1996), Russia (November 10, 1996), U.S. (November 15, 1996) and UK (November 15, 1996) to the International Court of Justice.
9 Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction, 1975.
10 Law of Land Warfare, U.S. Army, 1956, paragraph 35.
11 “Declaration on the Prohibition of the Use of Nuclear and Thermonuclear Weapons,” United Nations General Assembly Resolution 1653 (XVI), 24 November 1961.
12 Bukowski, G., D. Lopez, and F. McGehee, Uranium Battlefields Home and Abroad, Citizen Alert, March 1993, p. 43-54.
13 Ibid. at p.11.
14 Ibid. at p.48.
15 Advisory Opinion of the ICJ on the legality of the threat or use of nuclear weapons, op. cit. Dissenting Opinion of Judge Weeramantry, p. 43.
16 ICJ opinion, op. cit., p. 31.
17 Ibid., p.21.
18 ICJ opinion. Dissenting opinion of Judge Weeramantry, op. cit., p.56.