Nuclear Weapons

Roger S Clark. Encyclopedia of Genocide and Crimes Against Humanity. Editor: Dinah L Shelton. Volume 2. Detroit: Macmillan Reference USA, 2005.

Genocide and crimes against humanity can be carried out with machetes. They can be carried out with nuclear weapons. It appears, however, that in the current state of international law, using a nuclear weapon on people may not, in itself, be genocide, a crime against humanity, or otherwise absolutely forbidden.

The Nuclear Age arrived in the desert near Los Alamos, New Mexico, on July 16, 1945, with the first nuclear test detonation. That same year, the bombs were dropped from U.S. planes on the Japanese cities of Hiroshima, on August 6, and Nagasaki, three days later. Hiroshima and Nagasaki have been the only uses of nuclear weapons in armed conflict.

Subsequently, the Soviet Union, the United Kingdom, France, and China became avowed members of the Nuclear Club. The United States and the Soviet Union tested hydrogen devices of ever more awesome power. Israel is widely believed to have nuclear weapons. South Africa probably had the capability but fors-wore development after the demise of apartheid. India and Pakistan tested devices in 1998. North Korea apparently has the capability, and Iran, Iraq, Libya, and Brazil have been suspected of developing it. Iraq’s nuclear potential was a significant factor in the efforts by the United Nations and the International Atomic Energy Agency (IAEA) to control that country’s development of weapons of mass destruction following the Gulf War of 1991. (The IAEA is an intergovernmental organization associated with the United Nations that is devoted to encouraging peaceful uses of nuclear energy.) Nuclear potential figured prominently in the rationale articulated by the United States for its pre-emptive invasion of Iraq in 2003.

Nuclear weapons are explosive devices whose energy comes from fusion or fission of the atom. Their explosion releases vast amounts of heat and energy as well as immediate and long-term radiation. Radiation, unique to nuclear weapons, can cause nearly immediate death and long-term sickness, as well as genetic defects and illness in future generations. Nuclear weapons can have dramatically greater explosive effect than conventional weapons. The bomb dropped on Hiroshima from the airplane named Enola Gay was the explosive equivalent of approximately three thousand B29 bombers carrying conventional bombs. The “Bravo” hydrogen test at Bikini Atoll in 1954 had one thousand times the power of the Hiroshima blast.

The Case of Hiroshima and Nagasaki

What might international law say of such forces? The first legal assessment came as a protest from the Japanese Imperial Government through the Government of Switzerland, four days after the bombing of Hiroshima. Referring to Articles 22 and 23 (e) of the Regulations respecting the Laws and Customs of War on Land annexed to the Hague Convention of 1907, the Japanese government emphasized the inability of a nuclear bomb to distinguish between combatants and belligerents, and the cruel nature of its effects, which it compared to poison and other inhumane methods of warfare. Article 22 of the Hague Regulations provides: “The right of belligerents to adopt means of injuring the enemy is not unlimited.” Article 23 (e) provides that “… it is especially forbidden … (e) To employ arms, projectiles, or material calculated to cause unnecessary suffering.” The Japanese protest decried “a new offence against the civilization of mankind.” Its adversary, however, emphasized how the use of the bomb had quickly brought the war to finality, with millions of lives saved by avoiding a sea and land assault on the Japanese mainland.

The Japanese protest appears as Exhibit III in Shimoda v. State, a case brought in the Tokyo District Court in 1963. The plaintiffs sought damages for injuries suffered in Hiroshima and Nagasaki. The plaintiffs argued the illegality of the use of nuclear weapons, founded on an expanded version of the 1945 protest. Damages were claimed from the Japanese government on the theory that it had, in the Peace Treaty, waived the rights of victims to obtain redress from the United States without supplying an alternative source of compensation. The court agreed that the bombings were illegal, but held there was no right to press a claim for damages against the Japanese government.

The concepts of genocide and crimes against humanity were not yet in wide usage when the Japanese government made its August 1945 protest. If the events had occurred a little later, after the concepts gained currency, the government might have added references to those concepts in its protest. Given the international conflict with the United States, however, it was natural to rely on the law of the Hague.

The general principles of the laws of armed conflict have been a major recurring theme in the efforts to rein in nuclear weaponry through international law. This strategy emphasizes banning the use (but not necessarily possession) of such weapons. Other means have included: the quest for partial or total nuclear disarmament (including efforts at non-proliferation and strategic arms limitation); attempts by treaty, resolutions in international organizations, and litigation to stop the testing of such devices; limitations on the development of delivery systems (and defenses thereto); and the creation of Nuclear Free Zones, such as Antarctica, the moon, the South Pacific, and Latin America.

Australia/New Zealand Law Suits

New Zealand incurred the wrath of its traditional allies in the 1980s by instituting a total ban from its ports of nuclear-armed and nuclear-powered vessels. In 1973 Australia and New Zealand endeavored to obtain a ruling from the International Court of Justice on the legality of French nuclear tests in the Pacific. Their arguments relied primarily on environmental law and the law of the sea. A majority of the court in effect held the case moot, without reaching a finding on the merits. France had, until the time of the proceedings, been testing in the atmosphere. It now announced that its future tests would be underground. The court held that this announcement was legally binding on the government, which meant that the object sought by Australia and New Zealand had been achieved.

The court, in vague language, left open the possibility of revisiting the case “if the basis of this Judgment were to be effected.” New Zealand believed that its case dealt not only with tests in the atmosphere, but also tests that resulted in the entry of radioactive material into the marine environment, even if the testing took place below the ground. Receiving indications that radioactive material was escaping from underground, New Zealand tried to resurrect its case in 1995. A majority of the court refused to reopen the case, taking a narrow view of the earlier proceedings and insisting that, like Australia’s somewhat differently worded case, only atmospheric testing had been at issue.

International Court of Justice Advisory Opinion

A further significant effort to draw the various legal strands together occurred in the mid-1990s with efforts at the World Health Organization (WHO) and the United Nations General Assembly to seek an advisory opinion from the International Court of Justice on the legality of the use, or threat of use, of nuclear weapons. Ultimately, a majority of the court held that the WHO’s efforts went beyond its constituted powers.

The court, however, had few qualms about trying to answer the concerns of the General Assembly, because the United Nation held much wider competence on questions regarding peace and security. The Assembly asked: Is the threat or use of nuclear weapons in any circumstance permitted under international law? The court rendered its opinion on July 8, 1996. States opposed to nuclear weapons argued that the use, or threat of use, of nuclear weapons is illegal in itself, any time and anywhere. Three of the fourteen judges on the court agreed. Seven more said that it would “generally” be contrary to the laws of war to use or threaten to use nuclear weapons. The seven added that they were not sure whether such a use “would be lawful or unlawful in an extreme circumstance of self-defence, in which the very survival of a State would be at stake.” Four judges, Stephen Schwebel (United States), Sheru Oda (Japan), Gilbert Guillaume (France), and Rosalyn Higgins (United Kingdom), disagreed with both of these positions: They believed that each individual case had to be considered against the relevant standards and that no general rule was possible.

The arguments primarily drew upon the law of armed conflict (humanitarian law); environmental law; human rights law (especially the right to life and the law relating to genocide); and the constitutional documents of the UN and the WHO—the UN Charter and the WHO Constitution. Opponents of nuclear weapons argued that these bodies of law pointed, individually or cumulatively, in the direction of the illegality of nuclear weapons. Instruments such as the Partial Test Ban Treaty (PTBT) of 1963 and the Non-Proliferation Treaty (NPT) of 1968 were said to provide further indications of the aversion of international law to nuclear weaponry. The 1963 treaty bans nuclear weapons tests in the atmosphere, in outer space, and under water. The NPT recognizes that the original five nuclear powers—the United States, Russia, The United Kingdom, France and China—already have the weapons, but it nonetheless tries to keep others from developing them.

The essence of the argument by the nuclear powers was that none of these bodies of law expressly addresses the use of nuclear weapons and that, consequently, there was nothing to prohibit their use, or the threat of their use. Moreover, the NPT, they contended, legitimized the possession and thus potential use of nuclear weapons. The benevolent intentions of the nuclear powers were said to be supported by the “negative security guarantees” given in 1995 by the United States, Russia, the United Kingdom, and France. Essentially, they promised not to use nuclear weapons on a non-nuclear state, unless that state carried out an attack in association or alliance with a nuclear-weapon state. (China made a similar promise, without the exception.) Many developing countries, on the other hand, saw the NPT as discriminatory.

After initial discussion of the court’s jurisdiction and of the question itself, the court addressed the arguments that were based on human rights and environmental law. It suggested that human rights arguments are inconclusive where nuclear weapons are concerned because they ultimately send the enquiry to the laws of armed conflict. The court then held that the laws of armed conflict amount to alex specialis in the present context. In other words, the provisions of the laws of armed conflict would prevail over the more general precepts of human-rights law. The same was true of the environmental arguments. “Respect for the environment is one of the elements that go to assessing whether an action is in conformity with the principles of necessity and proportionality [in the laws of armed conflict].” Similarly, the provisions of the UN Charter on when force is, or is not, lawful do not get to the ultimate conclusion. They have to be read subject to the laws of war—even lawful self defense is subject to the constraints of those rules.

Of particular interest is the discussion of genocide. Some nations had contended that the prohibition contained in the 1948 Convention was a relevant rule of customary law that the court must apply to nuclear weapons. Article I of the Genocide Convention confirms that it applies “in time of peace or in time of war.” The court summarized the arguments as follows:

It was maintained before the Court that the number of deaths occasioned by the use of nuclear weapons would be enormous; that the victims could, in certain cases, include persons of a particular national, ethnic, racial, or religious group; that the intention to destroy such groups could be inferred from the fact that the user of the nuclear weapon would have omitted to take account of the well-known effects of the use of such weapons.

According to the court, however, this might sometimes be the case; sometimes not:

The Court would point out in that regard that the prohibition of genocide would be pertinent in this case if the recourse to nuclear weapons did indeed entail the element of intent, towards a group as such, required by the provision quoted above. In the view of the Court, it would only be possible to arrive at such a conclusion after having taken due account of the circumstances specific to each case.

While the Court did not specifically address it, the logic of its argument on genocide must apply also to the invocation of crimes against humanity in the attempt to ban the use of nuclear weapons. Unless the thresholds for a crime against humanity can be shown—an attack on a civilian population, and knowledge of that attack—there is no crime against humanity. Use of a nuclear weapon may, in some ill-defined circumstances, be justified or excused. In others it may be the engine of a crime against humanity. The court saw itself as concerned with international conflict. It could be argued that the most likely kind of case where it would be necessary to concentrate, for purposes of legal analysis, on genocide and crimes against humanity following the use of a nuclear weapon will be in the case of an internal conflict. In that context, the laws of armed conflict are still developing, and there the victims are not in a position to engage in the kind of armed resistance that would bring those laws into play. Thus the court arrived at what it regarded the nub of the debate: the laws of armed conflict.

Opponents of nuclear weapons argued that existing treaty provisions and customary law were broad enough to proscribe nuclear weapons, even though the laws do not say so explicitly and for the most part had been written before nuclear weapons were invented. The laws’ relevance could be found, for example, by interpreting treaties (and customary law) that ban the use in armed conflict of items such as poison or asphyxiating substances as also including nuclear weapons. Alternatively, one could look to international customary law (anchored mainly in a series of General Assembly resolutions) specifically proscribing nuclear weapons. Another way to achieve the same end would be to acknowledge that it is impossible to use nuclear and other weapons of mass destruction without contravening the prohibitions of unnecessary suffering, indiscriminate attacks which include civilians as targets, and breaches of the neutrality of non-participants in the conflict. Eleven members of the court thought otherwise, however, stating, “There is in neither customary nor conventional international law any comprehensive and universal prohibition of the threat or use of nuclear weapons as such.”

Views of the Court

So far as treaty language banning specific weapons goes, these eleven members did not regard what nuclear weapons do to people as bringing them within prohibitions relating to asphyxiating gases or poisons. Apparently, what radiation does is just incidental to the prime effect of nuclear energy, namely, to blow people to smithereens or to incinerate them. That is different from poisoning or asphyxiating and thus acceptable, or at least not illegal by virtue of the ban on poisons or gases. Moreover, the various treaties on nuclear-free areas and the NPT do not create a general prohibition on the use of nuclear weapons.

Nor did the eleven regard numerous nuclear-specific General Assembly resolutions as sufficient. The series of General Assembly resolutions in question begin with Resolution 1653 of November 24, 1961: the Declaration on the Prohibition of the Use of Nuclear and Thermo-Nuclear Weapons. Adopted by a majority of 55 to 20, with 26 abstentions, it asserted, “Any State using nuclear and thermo-nuclear weapons is to be considered as violating the Charter of the United Nations, as acting contrary to the laws of humanity, and as committing a crime against mankind and civilization.” The reference to the laws of humanity evokes the Martens Clause in the preamble to the Fourth Hague Convention of 1907. This clause asserts that, until a more complete code has been attained for the laws of war, “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.” In the 1981 Declaration on the Prevention of Nuclear Catastrophe, also adopted by a large majority, the Assembly declared, “States and statesmen that resort first to the use of nuclear weapons will be committing the gravest crime against humanity.” There is a close historical connection between the Martens Clause and the development of the concept of a crime against humanity, of which genocide is one branch.

Scholars usually assert that customary international law has two elements: consistent practice and a sense of obligation (or opinio juris) concerning that practice. The court acknowledged that although the General Assembly has no general law-making power, its resolutions may have a role in ascertaining customary law:

General Assembly resolutions, even if they are not binding, may sometimes have normative value. They can, in certain circumstances, provide evidence important for establishing the existence of a rule or the emergence of an opinio juris. To establish whether this is true of a given General Assembly resolution, it is necessary to look at its content and the conditions of its adoption; it is also necessary to see whether an opinio juris exists as to its normative character. Or a series of resolutions may show the gradual evolution of the opinio juris required for the establishment of a new rule.

The eleven did not see the failure to use nuclear weapons since 1945 and the practice represented by the line of GA resolutions as enough:

[S]everal of the resolutions under consideration have been adopted with substantial numbers of negative votes and abstentions; thus, although those resolutions are a clear sign of deep concern regarding the problem of nuclear weapons, they still fall short of establishing the existence of an opinio juris on the illegality of the use of such weapons.

The opinion then turns to principles of the law of war, such as unnecessary suffering, indiscriminate targeting, and breaches of neutrality, which the court locates in an overlapping mixture of customary and treaty law. All fourteen judges agreed that these principles apply to nuclear weapons. The opinion even cites statements by the nuclear powers to this effect in the oral pleadings. It is the implication of these principles, which leads to a sharp divergence. “The Court” (in fact seven of the judges, with the tie broken by the unusual rule of the court that gives the President the right to cast a tie-breaking vote in addition to his normal one) offers some cryptic remarks on the topic, summarized at paragraph 105 (2) E of the opinion:

It follows from the above-mentioned requirements 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;

However, in view of the current state of international law, and the elements of fact at its disposal, the Court cannot conclude definitively whether the threat or use of nuclear weapons would be lawful or unlawful in an extreme circumstance of self-defense, in which the very survival of a State would be at stake.

The individual opinions of the seven in the “majority” covered a broad spectrum, particularly on the second sub-paragraph of Paragraph E, which dealt with the possible exceptional case—self-defense—when the use of nuclear weapons would not be contrary to international law regarding armed conflict. At one end, some seemed to have doubts about even the validity of the ultimate self-defense exception. At the other, some seemed to accept that there was an in extremis self defense exception.

The seven person dissent comprised two diametrically opposite groups. Judges Christopher Weeramantry, Abdul Koroma, and Mohamed Shahabuddeen voted against the majority finding because they felt that the opinion did not go far enough; Judges Stephen Schwebel, Sheru Oda, Gilbert Guillaume, and Rosalyn Higgins voted against it because they felt the opinion went too far. For Weeramantry, Koroma, and Shahabuddeen, the rules of armed conflict, the specific and the general, proscribe nuclear weapons in all circumstances. No conceivable use of nuclear weapons could comply with the rules. For Schwebel, Oda, Guillaume, and Higgins, the laws of armed conflict apply, but each individual use or threat of use must be considered on its own merits, as would be true of any other weapon that is lawful in itself.

One other inquiry, which the court addressed only inconclusively, related to the nuclear powers’ doctrine of deterrence, the argument that the possession of nuclear weapons deterred their use and intimidated non-nuclear nations who might otherwise be tempted to engage in aggression or to use nuclear or other weapons of mass destruction. During the cold war period, it was widely argued that the doctrine of Mutually Assured Destruction (MAD) meant that no leader would dare risk starting a nuclear war in which all might perish. While the court opined that it could not ignore the doctrine, it did not offer a legal characterization of it. Judge Schwebel, in his dissenting opinion, however, seemed to regard the doctrine as supportive of the nuclear powers’ position on customary law.

Having split three ways on the crucial issue, the court spoke unanimously regarding a certain matter that was not directly responsive to the question asked. It nonetheless points in the only possible direction now open regarding the issue of nuclear weapons. The presence of this matter in the court reflected widespread frustration that, after nearly thirty years, the promise of Article VI of the 1968 Non-Proliferation Treaty (NPT) had not been fulfilled. Article VI provides that:

Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to 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.

At the time that the Advisory Opinion was written, 182 countries were parties to the non-proliferation treaty. By the end of 2003, there were 188, but one had claimed to withdraw. The opinion reiterates the Article VI obligation in various ways, hinting that it applies (as customary law) to parties and (the few) non-parties to the treaty alike. There is an obligation both to negotiate in good faith and to achieve a particular result—total nuclear disarmament—as well as to reach the broader goal of general and complete disarmament.

The whole object of the case had been to delegitimize the nuclear bomb. No one doubted that ultimately it would still be necessary to complete the disarmament negotiations. Even total success in the case would not have magically eliminated existing stockpiles. The success of the case in chipping away at the acceptability of nuclear weapons should have made it a little more likely that those negotiations would be completed sooner rather than later.

Nuclear Nonproliferation

The NPT envisaged that conferences would be held at five-year intervals in order to review the operation of the treaty. Concluded in 1968 and in force in 1970, it was initially effective for a period of twenty-five years. In 1995, while the advisory proceedings were pending, the parties agreed that it would continue in force indefinitely. At the review in 2000, a group known as the “New Agenda Coalition” (Brazil, Egypt, Ireland, Mexico, New Zealand, South Africa, and Sweden) spearheaded the effort that resulted in an “unequivocal undertaking by the nuclear-weapons States to accomplish the total elimination of their nuclear arsenals leading to nuclear disarmament to which all States are committed under Article VI.”

It is hard to see this vision being realized. In 1997 Costa Rica submitted a Model Nuclear Weapons Convention to the United Nations. Its title says it all: “Convention on the Prohibition of the Development, Testing, Production, Stockpiling, Transfer, Use, and Threat of use of Nuclear Weapons and on Their Elimination.” It would lead to progressive prohibition and stringent inspections to ensure compliance. The model has been increasingly refined by nongovernmental groups, such as the Lawyers Committee on Nuclear Policy, but has not captured the imagination of governments. Negotiations proceed glacially in various forums, including the First Committee of the United Nations General Assembly, the sixty-six nation Conference on Disarmament which meets in Geneva and the Assembly’s Commission on Disarmament.

Although they have worked toward reducing their arsenals, the nuclear powers seem determined to rely on them in some circumstances, and even to continue research and development. Albeit observing a moratorium on testing, the United States, for example, seeks to develop a “mini-nuke” capable of going after deeply buried weapons of mass destruction. In December 2001, President Bush announced the United States’ withdrawal from the 1972 agreement with Russia on the limitation of anti-ballistic missile systems. That agreement complemented the two super-powers’ policy of Mutually Assured Destruction (MAD) and was a basic element of their search for deterrence. The 1972 treaty prohibited the parties from putting into place systems capable of defending their entire territories from intercontinental ballistic missiles and from developing, testing, or deploying sea-, air-, space-, or mobile land-based antiballistic missile systems.

Those in favor of withdrawing saw the treaty as an obstacle to developing a comprehensive defense against weapons of mass destruction. Those opposed feared the U.S. government would now embark on an incredibly expensive technological effort, which had no guarantee of success. At the same time, they argued, ending the treaty could result in a new arms race with Russia and even China. Meanwhile, a more pressing danger was posed by terrorists and rogue states with delivery systems other than intercontinental missiles. A relatively small “dirty bomb” or radiological instrument in the hands of terrorists might present a greater danger than a developed bomb, and resources might be better spent in dealing with such dangers.

In December of 2002, the United States issued a new “National Strategy to Combat Weapons of Mass Destruction” which asserts that the United States “reserves the right to respond with overwhelming force—including through resort to all of our options—to the use of WMD against the United States, our forces abroad, friends, and allies.” The phrase, “all of our options,” clearly includes both conventional and nuclear responses, even in “appropriate cases through preemptive measures.” This is perhaps even clearer than a similar statement made earlier in the year in a Nuclear Posture Review. Serious questions have been raised about the compatibility of these moves with the United Nations Charter and with the International Court of Justice’s opinion.

Three nations (India, Israel, and Pakistan) have remained resolutely outside the NPT. Another, North Korea, has purported to withdraw. It claims the right under a treaty provision (similar to that the United States invoked in withdrawing from the ABM treaty) that a party “shall in exercising its national sovereignty have the right to withdraw from the Treaty if it decides that extraordinary events, related to the subject matter of this Treaty, have jeopardized the supreme interests of its country.” North Korea asserted its security was jeopardized by the United States, which North Korea claimed was threatening a pre-emptive nuclear strike, other military action, and a blockade. North Korea’s right to withdraw is hotly debated.

Divisions and Debate

More positive have been developments involving the IAEA’s inspection regime. Under the NPT, the IAEA enters into safeguard agreements with non-nuclear weapons states to maintain controls over nuclear material for peaceful activities. Efforts to strengthen that system have been undertaken since 1992, with the discovery of the extent of Iraq’s weapons program, notwithstanding the safeguards. These efforts entailed the development of more intrusive reporting and inspection. States are encouraged to accept this by becoming party to an optional protocol, a model of which was developed by the Agency in 1997. Late in 2003, Iran agreed to such a protocol and Libya was about to. The IAEA inspections regime could provide a precedent, along with that developed by the Organization for the Prevention of Chemical Weapons, for a more comprehensive nuclear abolition treaty, along the lines of the model introduced by Costa Rica. Meanwhile, efforts continue to put greater international control over fissile material adaptable to bomb-making.

Shortly after the International Court of Justice rendered its opinion, in September 1996, the United Nations approved the Comprehensive Nuclear Test Ban Treaty (CTBT). Its rationale is expressed succinctly in a preambular paragraph:

The cessation of all nuclear weapon test explosions and all other nuclear explosions, by constraining the development and qualitative improvement of nuclear weapons and ending the development of advanced new types of nuclear weapons, constitutes an effective measure of nuclear disarmament and non-proliferation in all its aspects.

Parties undertake not to carry out any nuclear weapon test explosion or any other nuclear explosion, and to prevent any such nuclear explosion at any place under their control. At the end of 2003, the treaty was not yet in force. While it had over one hundred signatories, by its own terms it cannot come into effect until ratified by forty-four named States that possess nuclear reactors. About three-quarters of them had done so by 2004, including France, the Russian Federation, and the United Kingdom. There were notable holdouts, such as China, the United States (where the treaty was rejected in the Senate), India, Pakistan and North Korea.

An effort to include the use of nuclear weapons as a war crime in the Rome Statute of the International Criminal Court failed in 1998. In a negotiation based on finding consensus, a majority supported it but it was adamantly opposed by the Nuclear Club, and thus failed. The way was left open for re-examination in the future.

Perversely perhaps, the laws of armed conflict regulate the ethics and modalities of killing. They place an absolute ban on certain kinds of weapons, such as exploding bullets below a certain size, dum-dum (expanding) bullets, poison, asphyxiating gases, and bacteriological substances. Use of such weapons is always a war crime, no matter how good the cause. Judge Weeramantry, dissenting in the Nuclear Weapons Case, raised the fundamental question how such modalities can be proscribed, yet permit nuclear weapons to remain lawful:

At least, it would seem passing strange that the expansion within a single soldier of a single bullet is an excessive cruelty which international law has been unable to tolerate since 1899, and that the incineration in one second of a hundred thousand civilians is not. This astonishment would be compounded when that weapon has the capability, through multiple use, of endangering the entire human species and all civilization with it.

One might equally ask whether it is “passing strange” that use of a nuclear weapon is not yet genocide or a crime against humanity as a matter of law. But genocide, as defined in the Genocide Convention, requires a specific mental element, the “intent to destroy, in whole or in part, a national, ethnical, racial, or religious group, as such.” It will often be possible to infer such an intent from use of nuclear weapons, but apparently not always. A crime against humanity requires knowledge that what is being done is part of an attack on a civilian population. Again, inferences may be drawn, but some think that may not always be so.