Report of the Foreign and International Law Committee of the New York County Lawyers’ Association
On the Unlawfulness of the Use and Threat of Use of Nuclear Weapons
With the end of the Cold War, the United States’ reliance on nuclear weapons has substantially decreased. Yet the weapons are still with us, as is the policy of nuclear deterrence threatening the use of these weapons.
While during the Cold War, serious evaluation of the lawfulness of the use of such weapons was difficult, given the strategic position the United States was in vis-à-vis the Soviet Union and the United States’ heavy reliance on the policy of nuclear deterrence, now the tables are turned. The United States is the predominant conventional power in the world, and, in addition, the effectiveness of conventional weapons has substantially increased. As the United States has itself recognized, nuclear weapons have themselves become the enemy, more than any hostile power.
So the time seems opportune for the evaluation of the long-lingering issue as to the lawfulness of the use and threat of use of nuclear weapons. And it seems that the task of raising and addressing the issue falls uniquely to lawyers, particularly those interested in international law, Cold War thinking being so deeply entrenched in the public perception of the matter and the applicable legal rules being of such an esoteric nature.
We believe that the use and threat of use of nuclear weapons are unlawful under rules of law recognized by the United States.
The United States has long acknowledged the binding nature of international law, including the law of armed conflict. It has repeatedly recognized the strictures of the rules, inter alia, of necessity, proportionality, and discrimination under that law:
That it is unlawful to use weapons involving a level of force not necessary in the circumstances to achieve the military objective;
That it is unlawful to use weapons whose probable effects upon combatant or noncombatant persons or objects would likely be disproportionate to the value of the anticipated military objective; and
That it is unlawful to use weapons that cannot discriminate between military and civilian targets.
The United States has specifically recognized that under these rules it is unlawful to use weapons whose effects are uncontrollable and could not be controlled when the weapons were used. The United States has further recognized (and it is widely established) that the effects of nuclear weapons—including the radiation effects—are uncontrollable.
It seems evident that nuclear weapons are quintessentially the type of uncontrollable weapons whose use is prohibited under international law, including the rules of necessity, proportionality and discrimination.
The use of nuclear weapons is also prohibited under these rules because of the likely effects of such weapons, effects transcending levels that could be deemed necessary, proportionate or discriminate. Nuclear weapons are vastly destructive in their blast, heat, electromagnetic impulse, and radiation effects, threatening destruction of apocalyptic proportions, destroying whole nations, civilization as we know it, the habitability of the earth, and ultimately the human species.
While limited use of highly accurate tactical weapons can be hypothesized, even such use, in the types of circumstances in which it would take place, would likely lead to escalating use of nuclear and other weapons of mass destruction and resultant extreme effects extending widely in time and space. These weapons would only be intentionally resorted to, if ever, in the types of extreme circumstances where an extreme response would be likely.
The rules of the law of armed conflict are violated by prohibited acts committed willfully and recklessly as well as intentionally. The risks inherent in the use of nuclear weapons are known, foreseeable, and predictable, and could only be regarded as willfully and recklessly undertaken, in the types of circumstances, if any, in which the United States might resort to such weapons.
The effects of nuclear weapons would likely also be inconsistent with compliance with the underlying purposes of the law of armed conflict, including the following purposes specifically recognized by the United States: facilitation of the restoration of peace and friendly relations, the assurance of the survival of civilization and of the human species, and the preservation of minimum standards of civilization and common ground of rationality between enemies.
As long as the United States continues to follow the policy of nuclear deterrence threatening the use of these weapons, the risk of use remains very much with us, even with the end of the Cold War.
International law is also clear that it is unlawful to threaten to use weapons which it would be unlawful to use. Accordingly, we conclude that both the use and threat of use of nuclear weapons are unlawful and urge that the United States recognize such unlawfulness.
The Cold War is over and the Soviet Union and threat of Communist domination long gone, but the extensive arsenals of nuclear weapons developed to deal with those threats are still very much with us.
During the Cold War, the United States substantially relied upon nuclear weapons for its national security. From the dawn of the nuclear era, the United States had permitted the Soviets to become superior in conventional weapons capability, relying instead on nuclear weapons and the policy of deterrence, whereby it threatened a nuclear response to a Soviet conventional attack.
Now the tables are turned. The United States is the pre-eminent conventional power threatened by nuclear and other weapons of mass destruction held by States far weaker in conventional weapons. In a sense, the United States no longer needs nuclear weapons, at least not in the way it did before.
Even more importantly, it has been recognized by a substantial portion of the civilian and military leadership of the United States for many decades that these weapons are essentially not usable; they are not even weapons. Their primary value is in the threat of use, a threat that was no longer credible even during the Cold War and that is of dubious effect against terrorist groups and rogue nations.
Perhaps counter-intuitively, the recognition of unlawfulness would make a difference. As the United States lawyer, arguing the point in the recent Nuclear Weapons Advisory case before the International Court of Justice, expressed it,
[E]ach of the Permanent Members of the Security Council has made an immense commitment of human and material resources to acquire and maintain stocks of nuclear weapons and their delivery systems … . If these weapons could not lawfully be used in individual or collective self-defense under any circumstances, there would be no credible threat of such use in response to aggression … .
The 1998 detonation of nuclear devices by India and Pakistan, the continuing specter of nuclear trafficking from the disintegrated Soviet Union, and the increasing availability of long- range missiles capable of carrying nuclear weapons to the United States only highlight the practical immediacy of the issue. Such immediacy is also indicated by the fact that several of the missiles launched by the United States in August 1998 against targets in Afghanistan and Sudan reportedly landed in Pakistan, and similar supposedly highly accurate modern missiles launched by the United States in the 1991 Gulf War and the 1999 Kosovo operation ended up hitting the wrong targets.
Recognition of the unlawfulness of the use of these weapons would enable the United States to take the lead de-legitimizing these weapons, as has happened with chemical and biological weapons.
It is a political and psychological phenomenon that a nation, like a person, must be ready to have a particular insight, to integrate it into an overall mindset. We submit that the illegality of the use of nuclear weapon is an idea whose time has come, and that this idea could have a transforming impact on risks inherent in international confrontations.
Ironically, the international law approach, rather than being utopian, may offer the best prospect for a breakthrough in our nation’s dealing with these weapons. The delegitimization of nuclear weapons and perhaps eventually substantial denuclearization and regulation, as with chemical and biological weapons, ostensibly offer the prospect of greater security than the continuation of the regime of nuclear deterrence.
The Nuclear Weapons Advisory Opinion of the International Court of Justice
In 1994 the United Nations General Assembly voted to submit to the International Court of Justice, the judicial branch of the United Nations, for advisory opinion the question of whether the threat or use of nuclear weapons could ever be lawful. The World Health Organization submitted a similar request. Representatives of nations from throughout the world appeared and argued the matter.
Among the States appearing was the United States, which took the position it has maintained throughout the nuclear era: that the use of nuclear weapons is subject to the rule of law but cannot be evaluated in the abstract; rather, that each particular use must be examined individually.
Without even asserting the lawfulness of its high yield nuclear weapons making up the vast bulk of its arsenal, the United States drew the line of defense essentially at its relatively small number of low-yield precision nuclear weapons.
The ICJ, in its 1996 advisory opinion, mirrored the United States’ non-defense of the lawfulness of the use of large scale nuclear weapons, but found itself unable to decide whether a more limited use of nuclear weapons could ever be lawful.
Specifically, the Court determined that, because of the potential of nuclear weapons to destroy civilization and the entire ecosystem of the planet, the use of nuclear weapons would generally be unlawful, but that it was not in possession of sufficient facts to evaluate whether use of nuclear weapons (ostensibly, precision low-yield tactical ones) could be lawful in extreme circumstances of self-defense when a State’s survival was at stake.
The Court stated that it did not have sufficient facts to determine the validity of the argument of the United States and other nuclear weapons States to the effect that highly accurate low-yield tactical nuclear weapons could be used in such a way as to limit and control their effects.
Thus, the Court in its decretal paragraphs—the “dispositif”—stated 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,” but that “in view of the current state of international law, and of 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 Court further stated:
95 … [T]he principles and rules of law applicable in armed conflict—at the heart of which is the overriding consideration of humanity—make the conduct of armed hostilities subject to a number of strict requirements. Thus, methods and means of warfare, which would preclude any distinction between civilian and military targets, or which would result in unnecessary suffering to combatants, are prohibited. In view of the unique characteristics of nuclear weapons, to which the Court has referred above, the use of such weapons in fact seems scarcely reconcilable with respect for such requirements.
Binding Nature of International Law
It is beyond question that international law, including the rules of the law of armed conflict applicable to the use of nuclear and other weapons, are the law of the land. The United States has long recognized this. Political though the area of potential use of nuclear weapons may be and central to national defense policy, it is subject to established rules of law.
The U.S. Constitution provides that treaties entered into by the United States are “the supreme Law of the Land.” The Air Force Manual on International Law notes that “state and federal courts have declared international law to be part of the law of the land.” The manual states that the United States is bound to follow customary international law “not because a treaty requires it, but because international law imposes the obligation on all states.”
Applicability to Nuclear Weapons of the Rules of the Law of War
The United States, while taking the position that there is no per se rule banning the use of nuclear weapons, acknowledges that the use of such weapons is subject to the law of armed conflict, including the rules of proportionality, necessity, moderation, discrimination, civilian immunity, neutrality, and humanity.
Thus, in its memorandum to the International Court of Justice in connection with that Court’s consideration of the recent request by the U.N. General Assembly for an advisory opinion on the lawfulness of the use of nuclear weapons, the United States stated, “[T]he legality of use [of nuclear weapons] depends on the conformity of the particular use with the rules applicable to such weapons.”
The Naval/Marine Commander’s Handbook states that the use of nuclear weapons “against enemy combatants and other military objectives” is subject to the following principles:
the right of the parties to the conflict to adopt means of injuring the enemy is not unlimited;
it is prohibited to launch attacks against the civilian population as such; and
the distinction must be made at all times between persons taking part in the hostilities and members of the civilian population to the effect that the latter be spared as much as possible.
The handbook describes these rules as the “three fundamental principles” of the law of armed conflict.
The Air Force Commander’s Handbook, while stating that the United States “takes the position” that the use of nuclear weapons is not unlawful, confirms that such use is “governed by existing principles of international law.”
The Air Force Manual on International Law, while stating that “the use of explosive nuclear weapons, whether by air, sea or land forces, cannot be regarded as violative of existing international law in the absence of any international rule of law restricting their employment,” similarly recognizes that such use is subject to the principles of the law of war generally. The manual states that “[a]ny weapon may be used unlawfully, such as when it is directed at civilians and not at a military objective” or “to inflict unnecessary suffering.”
The manual states that, in comparing the military advantages to be secured by the use of a new weapon to the effects caused by the weapon, the following questions are relevant:
can the weapon be delivered accurately to the target;
would its use necessarily result in excessive injury to civilians or damage to civilian objects, so as to be termed an “indiscriminate weapon;”
would its effects be uncontrollable or unpredictable in space or time as to cause disproportionate injury to civilians or damage to civilian objects; and
would its use necessarily cause suffering excessive in relation to the military purpose which the weapon serves so as to violate that prohibition.
The Army in its International Law Manual states that the provisions of international conventional and customary law that “may control the use of nuclear weapons” include:
(1) Article 23(a) of the Hague Regulations prohibiting poisons and poisoned weapons;
(2) the Geneva Protocol of 1925 which prohibits the use not only of poisonous and other gases but also of “analogous liquids, materials or devices;”
(3) Article 23(c) of the Hague Regulations which prohibits weapons calculated to cause unnecessary suffering; and
(4) the 1868 Declaration of St. Petersburg which lists as contrary to humanity those weapons which “needlessly aggravate the sufferings of disabled men or render their death inevitable.”
Some States have argued that States have an overriding right of self-defense, trumping the limitations of the law of armed conflict, and that the ICJ in its Nuclear Weapons Advisory Opinion included language suggesting that there might be an overriding right of self-defense.
Great Britain’s attorney before the ICJ argued that the right of self-defense trumps the requirements of humanitarian law:
It was also said that no balance is possible between the suffering which would becaused by a use—any use—of a nuclear weapon and the military advantage which would be derived from that use. But such an abstract statement does not stand up to analysis. Let me take an example. A State or group of States is faced with invasion by overwhelming enemy forces. That State or group of States is certainly entitled to defend itself. If all the other means at their disposal are insufficient, then how can it be said that the use of a nuclear weapon must be disproportionate? Unless it is being suggested that there comes a point when the victim of aggression is no longer permitted to defend itself because of the degree of suffering which defensive measures will inflict. Such a suggestion is insupportable in logic and unsupported in practice.
Great Britain further argued:
But if the prohibition in Article 2, paragraph 4, extends to nuclear weapons, so too does the right of self-defense enshrined in Article 51. That is the most fundamental right of all, Mr. President, and it is preserved in terms which are general, not restrictive. It is impossible to argue that this fundamental, inherent right has been limited or abandoned on the basis of mere inferences drawn from other rules, whether conventional or customary. Moreover, the practice of those states vitally affected by such a rule shows that they entirely reject any such inference.
So also France argued that the law of war and particularly the rule of proportionality does not preclude a State’s using whatever weapon is militarily “appropriate” to withstand an attack.
The United States, in its oral and written presentations to the ICJ, contrary to asserting such broad notions of the rights of self-defense and sovereignty, acknowledged, as noted above, the general applicability to the use of nuclear weapons of the rules of proportionality, necessity, moderation, discrimination, civilian immunity, neutrality, and humanity.
Thus, in its memorandum to the ICJ on the General Assembly application, the United States stated, as noted above, “As in the use of other weapons, the legality of use depends on the conformity of the particular use with the rules applicable to such weapons.” U.S. lawyer John McNeill similarly stated, “The United States has long shared the view that the law of armed conflict governs the use of nuclear weapons—just as it governs the use of conventional weapons.”
The U.S. memorandum formulated the proportionality test as follows:
Whether an attack with nuclear weapons would be disproportionate depends entirely on the circumstances, including the nature of the enemy threat, the importance of destroying the objective, the character, size and likely effects of the device, and the magnitude of the risk to civilians.
Addressing this same question from a different perspective, the I.C.J. noted that various States had argued, based on dicta in the Lotus and Nicaragua cases, that international law is based on sovereignty and consent, such that States are permitted to do anything that is not precluded by treaty or conventional law. The Court concluded that it did not have to reach this issue, since “the nuclear-weapon States appearing before it either accepted, or did not dispute, that their independence to act was indeed restricted by the principles and rules of international law, more particularly humanitarian law, as did the other States which took part in the proceedings.”
As to the right of self-defense, the Court stated that the question it was leaving open was that of the right of a state to use nuclear weapons in “an extreme circumstance of self-defense, in which [the State’s] very survival would be at stake.”
But then the Court, after noting that a State’s exercise of the right of self-defense must comply, inter alia, with the principle of proportionality, specifically stated that a “use of force that is proportionate under the law of self-defense, must in order to be lawful, also meet the requirements of the law applicable in armed conflict which comprise in particular the principles and rules of humanitarian law.”
The Court also quoted the statement on this point by the United Kingdom, “Assuming that a State’s use of nuclear weapons meets the requirements of self-defense, it must then be considered whether it conforms to the fundamental principles of the law of armed conflict regulating the conduct of hostilities.” The Court further emphasized in the final paragraph of its decision that the various grounds set forth in the Court’s decision were to be read in the light of one another.
The Court, notwithstanding a certain ambiguity, appears ultimately to have confirmed that all uses of force, including defensive ones of the most extreme sort, must comply with the law of armed conflict. We believe that the right of self-defense is subject to the rules of the law of armed conflict.
Rules of Proportionality, Necessity and Discrimination
Rule of Proportionality
The rule of proportionality prohibits the use of a weapon if its probable effects upon combatant or non-combatant persons or objects would likely be disproportionate to the value of the anticipated military objective.
The Naval/Marine Commander’s Handbook recognizes the proportionality requirement as a customary rule of international law and describes the requirement as codified in the prohibition by Additional Protocol I of attacks “which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects … which would be excessive in relation to the concrete and direct military advantage anticipated.” The handbook states that it is not unlawful to cause “incidental injury or death to civilian objects, during an attack upon a legitimate military objective,” but that such effects “should not be excessive in light of the military advantage anticipated by the attack.”
Rule of Necessity
The rule of necessity provides that, in conducting a military operation, a State, even as against its adversary’s forces and property, may use only such a level of force as is “necessary” or “imperatively necessary” to achieve its military objective, and that any additional level of force is prohibited as unlawful. The State must have an explicit military objective justifying each particular use of force in armed conflict and there must a reasonable connection between that objective and the use of the particular force in question. If a military operation cannot satisfy this requirement, the State must use a lower level of force or refrain from the operation altogether.
This is a rule of customary international law memorialized in numerous conventions. Violations of this rule served as the basis of convictions at Nuremberg. It is a rule of reason, requiring that a judgment be made as much in advance as possible by appropriately responsible decision-makers in light of the reasonably available facts. The State, in planning its military operations, is required to exercise all reasonable precautions to assure that the level of force to be used is within the scope of this rule. The protection of the rule runs to combatant as well as noncombatant persons and objects.
The rule precludes the use of a particular weapon if a less destructive weapon could reasonably be expected to achieve the objective, and outlaws the use of a weapon not capable of being regulated or not in fact regulated by the user. If the military objective is to take out a particular bridge and this can be accomplished through a direct attack on the bridge, it is unlawful to launch a massive attack against the entire county to take out the bridge. If the military objective could be achieved with conventional weapons, the use of nuclear weapons, with the appreciably higher likely levels of destruction, would generally be unlawful. If, on the other hand, it were necessary to destroy the county to take out the bridge, the necessity requirement would ostensibly be met if the other prerequisites were present, but, even then, if taking out the bridge had minor military value compared to the level of resultant devastation, the proportionality requirement would not be met and the strike would be prohibited.
The United States recognizes this rule. The Naval/Marine Commander’s Handbook states that the law of war seeks to prevent “unnecessary suffering and destruction” and thereby permits “only that degree and kind of force required for the partial or complete submission of the enemy with a minimum expenditure of time, life and physical resources.” The handbook repeats that the employment of “any kind or degree of force not required” for that purpose “is prohibited” and quotes with approval the statement in The Hostage Case that the destruction of property in war “to be lawful must be imperatively demanded by the necessities of war” and that there must be some “reasonable connection between the destruction of property and the overcoming of the enemy forces.” The handbook emphasizes that the protection of this rule extends to both combatants and noncombatants.
Rule of Discrimination
The rule of discrimination prohibits the use of a weapon that cannot discriminate in its effects between military and civilian targets. This is a rule designed to protect civilian persons and objects. The law recognizes that the use of a particular weapon against a military target may cause unintended collateral or incidental damage to civilian persons and objects and permits such damage, subject to compliance with the other applicable rules of law, including the principle of proportionality. However, the weapon must have been intended for—and capable of being controlled and directed against—a military target, and the civilian damage must have been unintended and collateral or incidental.
Thus, if the weapon or its effects were not susceptible of being controlled and directed against a military target in the first place, the resultant damage to civilian persons and objects would not be unintended, collateral or incidental—and the use would be prohibited. Similarly, if the very purpose of the strike were to put pressure on the adversary through attacks on its population (the classic Cold War deterrence theory of “mutual assured destruction” or “MAD”), the strike would be unlawful.
The discrimination requirement is recognized by the United States. The Air Force Commander’s Handbook states that a weapon is not unlawful “simply because its use may cause incidental casualties to civilians, as long as those casualties are not foreseeably excessive in light of the expected military advantage,” but that weapons that are “incapable of being controlled enough to direct them against a military objective” are unlawful. The Air Force Manual on International Law defines indiscriminate weapons as those “incapable of being controlled, through design or function,” such that they “cannot, with any degree of certainty, be directed at military objectives.”
The Naval/Marine Commander’s Handbook states that the law of war “is based largely on the distinction to be made between combatants and noncombatants” and hence prohibits making noncombatants the “object of attack” or targeting them “as such” and requires that civilians be safeguarded against “injury not incidental” to attacks against military objectives.
Two of the three “fundamental principles of the law of war” identified by the handbook focus upon the requirement of discrimination:
2. It is prohibited to launch attacks against the civilian population as such.
3. Distinctions must be made between combatants and noncombatants, to the effect that noncombatants be spared as much as possible.
The handbook states that the foregoing points “2” and “3” were customary rules of international law codified for the first time in Additional Protocol I, articles 51(2) and 57(1), respectively.
Per Se Unlawfulness Under Established Principles of International Law
The Air Force Manual on International Law states that the use of a weapon may be unlawful based not only on “expressed prohibitions contained in specific rules of custom and convention,” but also on “those prohibitions laid down in the general principles of the law of war.
Similarly, in discussing how the lawfulness of new weapons and methods of warfare is determined, the manual states that such determination is made based on international treaty or custom, upon “analogy to weapons or methods previously determined to be lawful or unlawful,” and upon the evaluation of the compliance of such new weapons or methods with established principles of law, such as the rules of necessity, discrimination and proportionality.
The manual notes that the International Military Tribunal at Nuremberg in the case of the Major War Criminals found that international law is contained not only in treaties and custom but also in the “general principles of justice applied by jurists and practiced by military courts.”
The Air Force Manual on International Law further states that the practice of States “does not modify” the legal obligation to comply with treaty obligations since such obligations are “contractual in nature.”
The Army’s Law of Land Warfare states “[t]he conduct of armed hostilities on land is regulated by the law of land warfare which is both written and unwritten.”
The United States recognizes “analogy” as well as “general principles” as sources of the law of armed conflict. The Air Force Manual on International Law states:
The law of armed conflict affecting aerial operations is not entirely codified. Therefore, the law applicable to air warfare must be derived from general principles, extrapolated from the law affecting land or sea warfare, or derived from other sources including the practice of states reflected in a wide variety of sources. Yet the US is a party to numerous treaties which affect aerial operations either directly or by analogy.
The manual notes that per se unlawfulness is not limited to prohibitions established in treaties or customary law:
[A] new weapon or method of warfare may be illegal, per se, if it is restricted by international law including treaty or international custom. The issue is resolved, or attempted to be resolved, by analogy to weapons or methods previously determined to be lawful or unlawful.
It seems clear that the use of nuclear weapons can be unlawful per se regardless of whether there is a treaty or custom establishing such unlawfulness.
We note that, unlike the statements of the rules of necessity, proportionality and discrimination, this point may be controversial. The United States argued before the ICJ that there is no per se rule banning the use of nuclear weapons because the United States has not consented to any such rule, and hence that each contemplated use of such weapons must be evaluated on an ad hoc basis.
The United States’ essential position is that it is only bound by conventional law specifically agreed to by the United States and customary law established by the practice of the community of nations, including the nations specially involved (here, the nuclear powers), out of a sense of obligation. The United States concludes that, since it has not agreed to a convention specifically prohibiting the use of nuclear weapons and has not refrained from their use out of a sense of obligation, such use cannot be per se unlawful.
Conrad K. Harper, Legal Advisor of the United States Department of State, told the Court that its “starting point in examining the merits” should be “the fundamental principle of international law that restrictions on States cannot be presumed, but must be established by conventional law specifically accepted by them, or in customary law established by the conduct of the community of nations.”
Michael J. Matheson, the Deputy Legal Advisor, Department of State, in his presentation to the Court, made the same point: Restrictions upon States must “be found in conventional law specifically accepted by States, or in customary law generally accepted as such by the community of nations.” Matheson relied upon the Court’s statement in the Nicaragua case that:
“in international law there are no rules, other than such rules as may be accepted by the State concerned, by treaty or otherwise, whereby the level of armaments of a sovereign State can be limited.”
We conclude that the U.S. position on this point, as presented to the ICJ, overlooks the existence of other sources of international law, including general principles of law—sources which, as discussed above, have been specifically recognized by the United States as potential bases of per se rules. The U.S. position before the ICJ ignored the fact that the United States has recognized that the broad rules of the law of armed conflict—such as the rules of proportionality, necessity, discrimination, and neutrality— apply to nuclear weapons and that per se rules can arise from them. The U.S. statements in its military manuals are compelling and hence a per se rule of unlawfulness can arise under established principles of international law.
Uncontrollability as Connoting Unlawfulness
The United States has recognized that the rules of discrimination, necessity, and proportionality prohibit the use of weapons whose effects cannot be controlled by the user.
Uncontrollability under Rule of Discrimination
The Air Force Commander’s Handbook states that weapons that are “incapable of being controlled enough to direct them against a military objective” are unlawful. The Air Force Manual on International Law defines indiscriminate weapons as those “incapable of being controlled, through design or function,” such that they “cannot, with any degree of certainty, be directed at military objectives.”
In its military manuals the United States has acknowledged that the scope of this prohibition extends to the effects of the use of a weapon. The Air Force Manual on International Law states that indiscriminate weapons include those which, while subject to being directed at military objectives, “may have otherwise uncontrollable effects so as to cause disproportionate civilian injuries or damage.” The manual states that “uncontrollable” refers to effects “which escape in time or space from the control of the user as to necessarily create risks to civilian persons or objects excessive in relation to the military advantage anticipated.” It is noteworthy that this prohibition encompasses the causing of risks, not just injury.
As a “universally agreed illustration of an indiscriminate weapon,” The Air Force Manual on International Law cites biological weapons, noting that the uncontrollable effects from such weapons “may include injury to the civilian population of other states as well as injury to an enemy’s civilian population.” The Naval/Marine Commander’s Handbook states that such weapons are “inherently indiscriminate and uncontrollable.”
The Air Force Manual on International Law further cites Germany’s World War II V-1 rockets, with their “extremely primitive guidance systems” and Japanese incendiary balloons, without any guidance systems. The manual states that the term “indiscriminate” refers to the “inherent characteristics of the weapon, when used, which renders (sic) it incapable of being directed at specific military objectives or of a nature to necessarily cause disproportionate injury to civilians or damage to civilian objects.”
As an example of an indiscriminate weapon, The Air Force Commander’s Handbook similarly cites the use of unpowered and uncontrolled balloons to carry bombs, since such weapons are “incapable of being directed against a military objective.”
Uncontrollability under Rule of Necessity
The requirement that the level of force implicit in the use of a weapon be controllable and controlled by the user is a natural implication of the necessity requirement. If a State cannot control the level of destructiveness of a weapon, it cannot assure that the use of the weapon will involve only such a level of destructiveness as is necessary in the circumstances.
The Air Force Manual on International Law recognizes as a basic requirement of necessity “that the force used is capable of being and is in fact regulated by the user.”
Uncontrollability under Rule of Proportionality
So also, if the State using a weapon is unable to control the effects of the weapon, it is unable to evaluate whether the effects would satisfy the requirement of being proportionate to the concrete and direct military advantage anticipated from the attack or to assure such limitation of effects.
The Air Force Manual on International Law notes that the requirement of proportionality prohibits “uncontrollable effects against one’s own combatants, civilians or property.”
We believe these statements of the law are not controversial. What the United States put in contention before the ICJ and what it generally argues, as reflected in its military manuals, is that, as a matter of fact, it is able to control the effects of nuclear weapons.
The Fact of Uncontrollability
If the United States were ever to use nuclear weapons, it would likely be multiple strategic weapons, and any use of nuclear weapons, in the circumstances in which such use would likely take place, would likely result in escalation and other uncontrollable effects.
U.S. Acknowledgment of Uncontrollability
The U.S. position appears to be inconsistent with the nature of nuclear weapons and their effects; the make-up of the U.S. nuclear force structure; the circumstances, if any, in which the United States would likely resort to nuclear weapons; the types of nuclear weapons it would likely use in such circumstances; the accuracy with which it could deliver the weapons; and the likely responses of targeted States and their allies.
Outside the courtroom, the United States recognizes the potential uncontrollability of the effects of nuclear weapons. This can be seen from the Chairman of the Joint Chief’s Joint Pub 3-12, Doctrine for Joint Nuclear Operations, setting forth the current operational planning for the integrated use by U.S. forces of nuclear weapons in conjunction with conventional weapons:
[T]here can be no assurances that a conflict involving weapons of mass destruction could be controllable or would be of short duration. Nor are negotiations opportunities and the capacity for enduring control over military forces clear.
As noted by Judge Shahabuddeen in his dissent in the Nuclear Weapons Advisory Decision, the United States, in ratifying the Treaty of Tlatelolco, subscribed to the following statement of preamble as to the indiscriminate and excessive injury caused by nuclear weapons:
The preamble to the 1967 Treaty of Tlatelolco, Additional Protocol II of which was signed and ratified by the five [nuclear weapons states, including the United States], declared that the Parties are convinced
“That the incalculable destructive power of nuclear weapons has made it imperative that the legal prohibition of war should be strictly observed in practice if the survival of civilization and of mankind itself is to be assured.
That nuclear weapons, whose terrible effects are suffered, indiscriminately and inexorably, by military forces and civilian population alike, constitute, through the persistence of the radioactivity they release, an attack on the integrity of the human species and ultimately may even render the whole earth uninhabitable.”
The extreme and disproportionate effects threatened by nuclear weapons are acknowledged by the U.S. military in their operational policy, training, and planning. The Nuclear Weapons Joint Operations manual states:
US nuclear forces serve to deter the use of WMD [“weapons of mass destruction,” including chemical, biological, and nuclear weapons] across the spectrum of military operations. From a massive exchange of nuclear weapons to limited use on a regional battlefield, US nuclear capabilities must confront an enemy with risks of unacceptable damage and disproportionate loss should the enemy choose to introduce WMD into a conflict.
[S]omeday a nation may, through miscalculation or by deliberate choice, employ these weapons. [A]n opponent may be willing to risk destruction or disproportionate loss in following a course of action based on perceived necessity, whether rational or not in a totally objective sense. In such cases deterrence, even based on the threat of massive destruction, may fail.
The U.S. Nuclear Force Structure
The U.S. nuclear force structure is comprised predominantly of high kilotonnage strategic nuclear weapons threatening devastating effects. In its active arsenal, United States currently has some 7206 strategic versus 1070 tactical warheads, and, of those tactical warheads, none are limited to 10 kilotons or less, the military’s outer limit for “low” yield nuclear weapons.
The United States has professedly de-emphasized nuclear weapons, particularly tactical nuclear weapons. The Army and Marines have been de-nuclearized. The Navy no longer deploys non-strategic nuclear weapons and the Air Force has dramatically cut its tactical nuclear stockpile. The United States has also passed legislation outlawing research and development that could lead to production of a low-yield nuclear weapon, defined for that purpose as one with a yield of less than five kilotons.
Volatile and Extreme Circumstances of Any Possible Use
The United States recognizes the extreme risks inherent in the use of nuclear weapons.
Its essential policy is one of deterrence, based on the hope that the threat of the use of such weapons will preclude the need ever to use them. The United States would ostensibly only intentionally resort to nuclear weapons, if at all, in the most serious and extreme of military situations threatening the most fundamental interests of the United States or possibly its allies, circumstances that would by their nature be extremely volatile, pressured, and threatening to all concerned.
Such a situation would ostensibly only arise in the context of an adversary capable of inflicting severe injury on the United States or possibly its allies and with a perceived determination to do so. If the situation were deemed imperative enough to require nuclear weapons, it would likely be deemed to require the greater destructive capability of strategic nuclear weapons.
Particularly given the vagaries of targeting just one or a small number of missiles, the limitations of experience with the use of nuclear weapons and their delivery mechanisms, and the inherent volatility of the situation that by definition would exist, the United States, if it were to resort to nuclear weapons at all, would almost certainly do so in a way conducive to having maximum impact on the enemy, and hence would likely strike with multiple nuclear weapons. Any one weapon could fail or miss its target.
The pressure on a nuclear State to “use ‘em or lose ‘em” in a major nuclear confrontation, given the attractiveness of nuclear assets as targets and the inevitable escalation risks, as well as the risk that an adversary might be in a “launch on warning mode,” would foster the early use of multiple nuclear weapons, particularly fixed base “sitting duck” nuclear weapons and other vulnerable such weapons.
The circumstances in which the United States might actually resort to nuclear weapons would be unlikely in the end to be logical or controlled, and the likely bias would be towards over-use. Threat would have led to counter-threat and events, even technology, would have taken on a life of their own, contrary probably to either side’s desires or expectations. The enemy’s response and the circumstances of the fog of war, misperception, failure of command and control, and human and equipment failure would likely be driving events. Rationality, even self-preservation, would have been left behind.
Use of Tactical Nuclear Weapons Unlikely
The United States, in defending the lawfulness of the use of nuclear weapons before the ICJ, argued that the use of a limited number of low-yield nuclear weapons could be used lawfully in non-urban areas. Such hypothetical low-yield surgical strikes at remote targets not precipitating escalation do not appear to be realistic in light of the full range of relevant facts.
While a very limited low-yield tactical nuclear strike against, say, a hardened underground WMD facility, such as Libya’s chemical weapons production facility at Tarhunah, might seem plausible, the United States either has or could develop a conventional capability to deal with such targets, and hence such use could not be deemed militarily or legally necessary.
The same is true of virtually any imaginable threat by a “rogue nation” to use nuclear, chemical or biological weapons. With the modern high technology revolution, our conventional weapons are sufficient not only to deter any threat but also to address virtually any military need, including virtually any threat that might otherwise have been the basis of using tactical nuclear weapons.
In any event, even the most limited of uses of the smallest of tactical nuclear weapons, in the circumstances in which such use would likely take place, would likely precipitate escalatory nuclear, chemical or biological attacks from the target state or one of its allies or some other adversary of the United States, whether because the enemy or some other State:
perceived the strike as a major strategic attack or anticipated such a strike;
saw the crossing of the nuclear threshold as the abandonment of restraint;
felt the need to demonstrate its own resolve and national standing or to warn the United States against further escalation;
felt the need to use its own nuclear weapons before they were destroyed by a further U.S. strike;
resolved to destroy U.S. nuclear weapons before more could be launched;
felt it could control escalation, going only one step up the escalatory ladder; or
was driven by bloodlust or suicidal vengefulness or human or equipment failure or cultural factors or the like.
The nuclear response by the adversary, or even the likelihood of such a response, would likely lead to escalating nuclear strikes by the United States for the same types of reasons that would have driven the enemy’s actions.
Given the fog of war and the inherent uncertainties as to the enemy’s perception of the attack and reaction thereto, a low level nuclear attack would have all the disadvantages of crossing the nuclear Rubicon, including substantially the same risks of precipitating escalation, without delivering the potential firepower of a strategic attack and without knocking out some of the enemy’s WMD capability.
Thus, if the strike was going to be perceived as a major nuclear attack, eliciting a response as if it were such an attack, it might as well be such an attack.
Uncontrollability of Risks as to Likely Escalation
The U.S. military’s recognition of the potential need for preemptive strikes against enemy delivery systems highlights the risks of escalation. As reflected in the Doctrine for Joint Theater Nuclear Operations, “Operations must be planned and executed to destroy or eliminate enemy WMD delivery systems and supporting infrastructure before they can strike friendly forces.”
Also inherently of an escalatory nature is the U.S. nuclear targeting doctrine of decapitation, as reflected in the Joint Theater Nuclear Operations manual, whereby the command and control centers of an opposing nation are “facilities that may be likely targets for nuclear strikes:”
Enemy combat forces and facilities that may be likely targets for nuclear strikes are:
WMD and their delivery systems, as well as associated command and control, production, and logistical support units;
Ground combat units and their associated command and control and support units.
The Joint Theater Nuclear Operations manual notes that “there may be a rapid escalation” once strikes against nuclear assets begin to affect “the forces available for nuclear employment.”
The military’s policies of concentration of force and redundant targeting, including “layering” and “cross-targeting,” potentially involving the use of multiple nuclear weapons, are inherently escalatory.
The quality of decisions being made will be affected by the severe time constraints caused by such factors as “the relatively short flight time of tactical missiles and potential increased uncertainty of mobile offensive force target locations.”
Noting that the joint force commander should have access to “near-real-time tradeoff analysis when considering the execution of any forces,” the Joint Theater Nuclear Operations manual states:
Very short timelines impact decisions that must be made. In a matter of seconds for the defense, and minutes for the offense, critical decisions must be made in concert with discussions with NCA.
The Joint Nuclear Operations manual also notes the risk of misperception and nonsusceptibility to deterrence, “It is possible that an adversary may misperceive or purposefully ignore a credible threat.”
Uncontrollability as to Delivery of Nuclear Weapons
U.S. nuclear weapons would typically be delivered to their targets by missiles based on either land, submarine, surface vessel or aircraft, or dropped by bombers.
Statistically, modern U.S. missiles are generally capable of extreme accuracy. A high percentage of missiles launched can be expected to strike within a close distance of their intended targets.
However, this tells only part of the story. The accuracy of any particular missile is uncertain and no one can know where it might end up.
Variables affecting this matter are legion, including the weather; gravitational effects; the accuracy of test or computational assumptions as to how the missile will perform and as to the location and nature of the target; the extent to which the launch was programmed and implemented correctly to reach the target; the extent to which the mechanical and electronic equipment in the missile functions as intended; the effect of the detonation of other nuclear or other weapons on performance; and the height at which the warhead detonates.