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| I. | Substantive International Law - First Part |
| 6. | USE OF FORCE AND RELATED PROBLEMS |
| 6.2. | Self-defence |
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Legality of the Threat or Use
of Nuclear Weapons
Advisory Opinion of 8 July 1996
I.C.J. Reports 1996, p. 226
[pp. 244-245] 40. The entitlement to resort to self-defense under
Article 51 is subject to certain constraints. Some of these constraints are
inherent in the very concept of self-defense. Other requirements are specified
in Article 51.
41. The submission of the exercise of the right of self-defense to the
conditions of necessity and proportionality is a rule of customary international
law. As the Court stated in the case concerning Military and Paramilitary
Activities in and against Nicaragua (Nicaragua v. United States of America):
there is a "specific rule whereby self-defense would warrant only
measures which are proportional to the armed attack and necessary to respond to
it, a rule well established in customary international law" (I.C.J.
Reports 1986, p. 94, para. 176). This dual condition applies equally
to Article 51 of the Charter, whatever the means of force employed.
42. The proportionality principle may thus not in itself exclude the use of
nuclear weapons in self-defense in all circumstances. But at the same time, 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.
43. Certain States have in their written and oral pleadings suggested that
in the case of nuclear weapons, the condition of proportionality must be
evaluated in the light of still further factors. They contend that the very
nature of nuclear weapons, and the high probability of an escalation of nuclear
exchanges, mean that there is an extremely strong risk of devastation. The risk
factor is said to negate the possibility of the condition of proportionality
being complied with. The Court does not find it necessary to embark upon the
quantification of such risks; nor does it need to Enquirer into the question
whether tactical nuclear weapons exist which are sufficiently precise to limit
those risks: it suffices for the Court to note that the very nature of all
nuclear weapons and the profound risks associated therewith are further
considerations to be borne in mind by States believing they can exercise a
nuclear response in self-defense in accordance with the requirements of
proportionality.
44. Beyond the conditions of necessity and proportionality, Article 51
specifically requires that measures taken by States in the exercise of the right
of self-defense shall be immediately reported to the Security Council; this
article further provides that these measures shall not in any way affect the
authority and responsibility of the Security Council under the Charter to take
at any time such action as it deems necessary in order to maintain or restore
international peace and security. These requirements of article51 apply whatever
the means of force used in self-defense.
[p. 263] 96. Furthermore, the Court cannot lose sight of the fundamental right of every State to survival, and thus its right to resort to self-defence, in accordance with Article 51 of the Charter, when its survival is at stake.
Nor can it ignore the practice referred to as ""policy of deterrence", to which an appreciable section of the international community adhered for many years. The Court also notes the reservations which certain nuclear-weapon States have appended to the undertakings they have given, notably under the Protocols to the Treaties of Tlatelolco and Rarotonga, and also under the declarations made by them in connection with the extension of the Treaty on the Non-Proliferation of Nuclear Weapons, not to resort to such weapons.
97. Accordingly, in view of the present state of international law viewed as a whole, as examined above by the Court, and of the elements of fact at its disposal, the Court is led to observe that it cannot reach a definitive conclusion as to the legality or illegality of the use of nuclear weapons by a State in an extreme circumstance of self-defense, in which its very survival would be at stake.
[p. 273 Decl. Bedjaoui] 22. A State's right to survival is also a fundamental law, similar in many respects to a "natural" law. However, self-defence - if exercised in extreme circumstances in which the very survival of a State is in question - cannot produce a situation in which a State would exonerate itself from compliance with the "intransgressible" norms of international humanitarian law. In certain circumstances, therefore, a relentless opposition can arise, a head-on collision of fundamental principles, neither one of which can be reduced to the other. The fact remains that the use of nuclear weapons by a State in circumstances in which its survival is at stake risks in its turn endangering the survival of all mankind, precisely because of the inextricable link between terror and escalation in the use of such weapons. It would thus be quite foolhardy unhesitatingly to set the survival of a State above all other considerations, in particular above survival of mankind itself.
[pp. 290-291 S.O. Guillaume] None of the States which appeared
before the Court raised the question of the relations between the right of
self-defence recognized by Article 5l of the Charter and the principles and
rules of the law applicable in armed conflict. All of them argued as if these
two types of prescription were independent, in other words as if the jus ad
bellum and the jus in bello congtituted two entities having no
relation with each other. In some parts of its Opinion the Court even seemed to
be tempted by such a construction. It may be wondered whether that is indeed the
case or whether, on the contrary, the rliles of the jus ad bellum may
not provide some clarification of the rules of the jus in bello.
The right of self-defence proc1aimed by the Charter of the United Nations is
characterized by the Charter as natural law. But Article 51 adds that nothing in
the Charter shall impair this right. The same applies 'a fortiori to
customary 1aw or treaty law. This conclusion 's eas'l explained, for no system
of law, whatever it may be, cou1d deprive one of its subjects of the right to
defend its own existence and safeguard its vita1 interests. Accordingly,
international law cannot deprive a State of the right to resort to nuc1ear
weapons if such action constitutes the u1timate means by which it can guarantee
its surviva1. In such a case the State enjoys a kind of "abso1ute defence"
("excuse absolutoire ") similar to the one which exists in all
systems of crimina1 law.
The Court did indeed identify this problem when, in paragraph 96 of the
Opinion, it stated that it cannot
"lose sight of the fundamental right of every State to survival, and thus its right to resort to se1f-defence, in accordance with Artic1e 51 of the Charter, when its surviva1 is at stake".
With this in mind, it pointed out in the same paragraph that "an appreciab1e section of the internationa1 community adhered for many years" to "the practice referred to as "po1icy of deterrence"'. It also stressed that States which adhered to this doctrine and this practice
"have always, in concert with certain other States, reserved the right to use those weapons in the exercise of the right to self-defence against an armed attack threatening their vital security interests" (para. 66).
"the reservations which certain nuclear-weapon States have appended to the undertakings they have given, notably under the Protocols to the Treaties of Tlatelolco and Rarotonga, and also under the declarations made by them in connection with the extension of the Treaty on the Non -Proliferation of Nuclear Weapons, not to resort to such weapons" (para. 96).
Lastly, the Court observed that the reservations to these Protocols and the ones contained in the declaratiods had "met with no objection from the parties to the Tlatelolco or Rarotonga Treaties or from the Security CouDcil" (para. 62). Indeed, it pointed out that the Security Council had noted with appreciation or welcomed the statements made in this connection (para. 45).
9. In these circumstances, the Court, in my view, ought to have carried its
reasoning to its conclusion and explicitly recognized the legality of deterrence
for defence of the vital interests of States. It did not do so explicitly, and
that is why I was unable to support operative paragraph 2 E. But it did so
implicitly, and that is why I appended to the Advisory Opinion a separate
opinion and riot a dissenting one.
In operative paragraph 2 E the Court decided in fact that it could not in
those extreme circumstances conclude definitively whether the threat or use of
nuclear weapons would be lawful or unlawful. In other words, it concluded that
in such circumstances the law provided no guide for States. But if the law is
silent in this case, States remain free to act as they intend.
[pp. 301-302 S.O. Ranjeva] In my view, the second clause of
paragraph 2 E raises difficulties of interpretation by virtue of the problem of
its intrinsic coherence in relation to the ru1es of the law of armed conflict
themselves, although its positive aspect must be emphasized: the principle that
the exercise of se1fdefence is subject to the rule of law.
Paragraph 2 E deals with the law of armed conflict and with humanitarian
law, the second branch of law applicable to the threat or use of nuclear weapons
(see para. 34). The 1aw of armed conflict is a matter of written law, while the
so-called Martens principle performs a residual function.
Two consequences flow from this: firstly, this law of armed conflict cannot
be interpreted as containing lacunae of the sort likely to warrant reserve or at
least doubt; secondly, nuclear weapons cannot be used outside the context of the
law of armed conflict. Moreover, since no State supported the principle of a
r6gime of non-law, the use of these weapons must be in conformity, from the
standpoint of the law, with the rules governing such conflict. In these
circumstances and on such an important question, there cannot be any doubt about
the validity of the principle of illegality in the law of armed conflict.
With regard to the substance of the law of armed conflict, the second clause
of operative paragraph 2 E introduces the possibility of an exception to the
rules of the law of armed conflict by introducing a notion hitherto unknown in
this branch of international law: the "extreme circumstance of
self-defence, in which the very survival of a State would be at stake". Two
criticisms must be offered. Firstly, the Court makes an amalgamation of the
rules of the Charter of the United Nations on the one hand and the law of armed
conflict and specifically the rules of humanitarian law on the other; whereas
paragraph 2 E deals only with the law of armed conflict, and the right of
self-defence belongs in paragraph 2 C. Rigorousness and clarity were necessary,
failing a paragraph 2 E bis separate from paragraph 2 E and the attachment of
the notion of "extreme circumstance of self-defence" to the more
general problem of self-defence dealt with in paragraph 2 C. Paragraph 2 C
covers all the cases of the right to use force by reference to the provisions of
the Charter (Arts. 2 and 4 and Art. 51). A priori nothing prohibits an
interpretation giving precedence to the rules of self-defence, including nuclear
self-defence, over the rules of humanitarian law, a difficulty which leads
consequentially to the second criticism. Secondly, the criticism is addressed to
the acceptance of this concept of "extreme circumstance of self-defence, in
which the very survival of a State would be at stake". There is no doubt
that the meaning of this concept is expressed in the norma1 meaning of the
words, but this observation is not sufficient for the purposes of legal
qualification.
The principal difficulty of the interpretation of the second clause of
paragraph 2 E lies in the true nature of the exception of "extreme
circumstance of self-defence" to the app1ication of humanitarian law and
the law of armed conflict. Neither the case-law of the Internationa1 Court or of
any other court nor the doctrine offer any authority to confirm the existence of
a distinction between the general case of app1ication of the rules of the law of
armed conflict and the exceptional case exempting a belligerent from fulfilling
the obligations imposed by those rules.
If such a rule must exist, it can be deduced only from the intention of the States authors of and parties to these instruments. The fact that the case of nuclear weapons was deliberately not addressed during the negotiation and conclusion of the major conventions on the law of armed conflict has been repeatedly stressed. Accordingly, it is difficult to see how these plenipotentiaries could envisage exceptions of such importance to the principles governing the law of armed conflict. These principles were mended to be applied in all cases of conflict without any particular consideration of the status of the parties to the conflict - whether they ere victims or aggressors. If an exceptional authorization had been envisaged, the authors of these instruments could have referred to it, for example by incorporating limits or exceptions to their universal application.
[pp. 306-307 S.O. Fleischhauer] 3. As the Court rightly sees it, the answer to the question asked of it by the General Assembly does not lie alone in a finding that the threat or use of nuclear weapons would be contrary to the rules of international law applicable in armed conflict, and in particular the principles and rules of humanitarian law. Through the use of the word "generally" in the first paragraph of point 2 E of the Conclusions and through the addition of the second paragraph to that point, the Court points to qualifications that apply or may apply to its findings regarding irreconcilability between the use of nuelcar weapons and humanitarian law. The word "generally" limits the finding as such; and according to the second paragraph,
"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-defence, in which the very survival of a State would be at stake".
To end the matter with the simple statement that recourse to nuclear weapons would be contrary to international law applicable in armed conflict, and in particular the principles and rules of humanitarian law, would have meant that the law applicable in armed conflict, and in particular the humanitarian law, was given precedence over the inherent right of individual or collective self-defence which every State possesses as a matter of sovereign equality and which is expressly preserved in Article 51 of the Charter. That would be so because if a State is the victim of an all-out attack by another State, which threatens the very existence of the victimized State, recourse to the threat or use of nuclear weapons in individual (if the victimized State is a nuclear-weapon State) or collective (if the victim is a non-nuclear-weapon State allied to a nuclear-weapon State) self-defence could be for the victimized State the last and only alternative to giving itself up and surrender. That situation would in particular exist if the attack is made by nuclear, bacteriological or chemical weapons. It is true that the right of self-defence as protected by Article 5l of the Charter is not weapon-specific (paragraph 39 of the considerations of the Opinion). Nevertheless, the denial of the recourse to the threat or use of nuclear weapons as a legal option in any circumstance could amount to a denial of self-defence itself if such recourse was the last available means by way of which the victimized State could exercise its right under Article 51 of the Charter.
A finding that amounted to such a denial therefore would not, in my view, have been a correct statement of the law; there is no rule in international law according to which one of the conflicting principles would prevail over the other. The fact that the attacking State itself would act in contravention of international law, would not alter the situation. Nor would recourse to the Security Council, as mandated by Article 51, guarantee by itself an immediate and effective relief.
[pp. 308-309 S.O. Fleischhauer] The principles and rules of the humanitarian law and the other principles f law applicable in armed conflict, such as the principle of neutrality on the one side and the inherent right of self-defence on the other, which are through the very existence of the nuclear weapon in sharp opposition to each other, are all principles and rules of law. None of these principles and rules is above the law, they are of equal rank in law and they can be altered by law. They are justifiable. Yet international law has so far not developed - neither in conventional nor in customary law - a norm on how these principles can be reconciled in the face of the nuclear weapon. As I stated above (paragraph 3 of this separate opinion), there is no rule giving prevalence of one over the other of these principles and rules. International politics has not yet produced a system of collective security of such perfection that it could take care of the dilemma, swiftly and efficiently.
In view of their equal ranking this means that, if the need arises, the smallest common denominator between the conflicting principles and rules has to be found. This means in turn that, although recourse to nuclear weapons is scarcely reconcilable with humanitarian law applicable in armed conflict as well as the principle of neutrality, recourse to such weapons could remain a justified legal option in an extreme situation of individual or collective self-defense in which the threat or use of nuclear weapons is the last resort against an attack with nuclear, chemical or bacteriological weapons or otherwise threatening the very existence of the victimized State. The same result is reached if, in the absence of a conventional or a customary rule for the conciliation of the conflicting legal principles and rules, it is accepted that the third category of law which the Court has to apply by virtue of Article 38 of its Statute, that is, the general principles of law recognized in all legal systems, contains a principle to the effect that no legal system is entitled to demand the self-abandonment, the suicide, of one of its subjects. Much can be said, in my view, in favour of the applicability of such a principle in all modern legal systems and consequently also in international law.
[p. 417 D.O. Shahabuddeen] There would be difficulty also in following how it is that what is inalienable for some States is alienable for others. It is an attribute of sovereignty that a State may by agreement restrain the exercise of its competence; yet how far it may do so without losing its status as a State is another question1. Since the right of self-defence is "inherent" in a State, it is not possible to conceive of statehood which lacks that characteristic. See the illustration in General Assembly resolution 49/10 of 3 November 1994,
"[r]eaffirming ... that as the Republic of Bosnia and Herzegovina is, a sovereign, independent State and a Member of the United Nations, it is entitled to all rights provided for in the Charter of the United Nations, including the right to self-defence under Article 51 thereof".
Arrangements for the exercise of the right of self-defence are a different matter. But, so far as the right itself is concerned, if the right includes a right to use nuclear weapons, the latter is not a small part of the former. It was no doubt for this reason that, in the parallel case brought by the World Health Organization, it was argued that to "deny the victim of aggression the right to use the only weapons which might save it would be to make a mockery of the inherent right of self-defence"2. The argument is understandable, granted the premise that the right to use nuclear weapons is part of the inherent right of self-defence. The question is whether the premise is correct. For, if it is correct, then, by the same token, there is difficulty in seeing how the NNWS which were parties to the NPT could have wished to part with so crucially important a part of their inherent right of self-defence.
[pp. 418-419 D.O. Shahabuddeen] These difficulties suggest that it is necessary to distinguish between the inherent right of self-defence and the means by which the right is exercisable. A State using force in self-defence is acting legally under the jus ad bellum. But, whether a State is acting legally or illegally under the jus ad bellum, if it is in fact using force it must. always do so in the manner prescribed by the jus in bello. It is the jus in bello which lays down whether or not a particular means of warfare is permissible. Thus, where the use of a particular weapon is proscribed by the jus in bello, the denial of the use of that weapon is not a denial of the right of self-defence of the attacked State: the inherent right of self-defence spoken of in Article 51 of the Charter simply does not comprehend the use of the weapon in question. The legal answer to the possible plight of the victim State is given by the principle, as enunciated by the United States Military Tribunal at Nuremberg on 19 February 1948, that "the rules of international law must be followed even if it results in the loss of a battle or even a war. Expediency or necessity cannot warrant their violation ...".
[pp. 426-427 D. O. Shahabuddeen] Thus, however gross or excessive the suffering, the presence of the stated circumstances could create an exception to the application of humanitarian law, as indeed is visualized by the word "generally" in the first part of that subparagraph of the Court's holding. A law may, of course, provide for exceptions to its application. At the moment, however, there is nothing to suggest that humanitarian law Provides for an exception to accommodate the circumstances visualized by the Court. It seems to me that to take the position that humanitarian law can be set aside in the stated circumstances would sit oddly with the repeated and correct submissions on the part of both sides to the argument that the Court should apply the law and not make new law.
One further point. Despite variations in formulation and references to the concept of "vital security interests", an "extreme circumstance of self-defence, in which the very survival of a State would be at stake", as defined by the Court, is the main circumstance in which the proponents of legality advance a claim to a right to use nuclear weapons. This is so for the reason that, assuming that the use of nuclear weapons is lawful, the nature of the weapons, combined with the limitations imposed by the requirements of necessity and proportionality which condition the exercise of the right of self-defence, will serve to confine their lawful use to that "extreme circumstance". It follows that to hold that humanitarian law does not apply to the use of nuclear weapons in the main circumstance in which a claim to a right of use is advanced is to uphold the substance of the thesis that humanitarian law does not apply at all to the use of nuclear weapons. That view has long been discarded; as the Court itself recalls, the NWS themselves do not advocate it. I am not Persuaded that that disfavoured thesis can be brought back through an exception based on self-defence.
[p. 513 D.O. Weeramantry] If a nation is attacked, it is clearly entitled under the United Nations Charter to the right of self-defence. Once a nation thus enters into the domain of the jus in bello, the principles of humanitarian law apply to the conduct of self-defence, just as they apply to the conduct of any other aspect of military operations. We must hence examine what principles of the jus in bello apply to the use of nuclear weapons in self-defence.
The first point to be noted is that the use of force in self-defence (which is an undoubted right) is one thing and the use of nuclear weapons in self-defence is another. The permission granted by international law for the first does not embrace the second, which is subject to other governing principles as well.
All of the seven principles of humanitarian law discussed in this opinion apply to the use of nuclear weapons in self-defence, just as they apply to their use in any aspect of war. Principles relating to unnecessary suffering, proportionality, discrimination, non-belligerent States, genocide, environmental damage and human rights would all be violated, no less in self-defence than in an open act of aggression. The jus in bello covers all use of force, whatever the reasons for resort to force. There can be no exceptions, without violating the essence of its principles.
[p. 561 D.O. Koroma] As already stated, the Court's present finding represents a challenge to some of the fundamental precepts of existing international law including the proscription of the use of force in international relations and the exercise of the right of self-defence. That the Court cannot decide definitively whether the use of nuclear weapons would be lawful or unlawful when the survival of the State is at stake is a confirmation of the assertion that the survival of that State is not only not a matter for the law but that a State, in order to ensure its survival, can wipe out the rest of humanity by having recourse to nuclear weapons. In its historical garb "of the fundamental right of self-preservation", such a right was used in the past as a pretext for the violation of the sovereignty of other States. Such acts are now considered unlawful under contemporary international law.
[pp. 562-563 D.O. Koroma] The question therefore is not whether a State is entitled to exercise its right of self-defence in an extreme circumstance in which the very survival of that State would be at stake, but rather whether the use of nuclear weapons would be lawful or unlawful under any circumstance in which its very survival was at stake - or, in other words, whether it is possible to conceive of consequences of the use of such weapons which do not entail an infringement of international law applicable in armed conflict, particularly international humanitarian law. As stated above, in terms of the law. the right of self-defence is restricted to the repulse of an armed attack and does not permit of retaliatory or punitive action. Nor is it an exception to the jus in bello (conduct of hostilities). Since, in the light of the law and the facts, it is inconceivable that the use of nuclear weapons would not entail an infringement of, at the very least, the law applicable in armed conflict, particularly humanitarian law, it follows that the use of such weapons would be unlawful. Nuclear weapons do not constitute an exception to humanitarian law.
[p. 591 D.O. Higgins] 33. Perhaps the reference to "the current state of international law" is a reference to perceived tensions between the widespread acceptance of the possession of nuclear weapons (and thus., it may be presumed, of the legality of their use in certain circumstances) as mentioned by the Court in paragraphs 67 and 96 on the one hand, and the requirements of humanitarian law on the other. If so, I believe this to be a false dichotomy. The pursuit of deterrence, the shielding under the nuclear umbrella, the silent acceptance of reservations and declarations by the nuclear powers to treaties prohibiting the use of nuclear weapons in certain regions, the seeking of possible security assurances - all this points to a significant international practice which is surely relevant not only to the law of self-defence but also to humanitarian law. If a substantial number of States in the international community believe that the use of nuclear weapons might in extremis be compatible with their duties under the Charter (whether as nuclear powers or as beneficiaries of "the umbrella" or security assurances) they presumably also believe that they would not be violating their duties under humanitarian law.
34. Nothing in relevant statements made suggests that those States giving nuclear assurances or receiving them believed that they would be violating humanitarian law - but decided nonetheless to act in disregard of such violation. In sum,, such weight as may be given to the State practice just referred to has a relevance for our understanding of the complex provisions of humanitarian law as much as for the provisions of the Charter law of self-defence.
| 1 | See argument of M. Yasseen in I.C.J. Pleadings, Interpretation of the Agreement of 25 March 1951 between the WHO and Egypt, pp. 298-299. |
| 2 | Statement of the Government of the United Kingdom (para. 24), in the case concerning Legality of the Use by a State of Nuclear Weapons in Armed Conflict (Request for Advisory Opinion). |
