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I. Substantive International Law - First Part
4.2. States
4.2.5. Fundamental Rights and Obligations Sovereignty

¤ Legality of the Threat or Use
of Nuclear Weapons
Advisory Opinion of 8 July 1996
I.C.J. Reports 1996, p. 226

[pp. 238-239] 21. The use of the word "permitted" in the question put by the General Assembly was criticized before the Court by certain States on the ground that this implied that the threat or the use of nuclear weapons would only be permissible if authorization could be found in a treaty provision or in customary international law. Such a starting point, those States submitted, was incompatible with the very basis of international law, which rests upon the principles of sovereignty and consent; accordingly, and contrary to what was implied by use of the word "permitted", States are free to threaten or use nuclear weapons unless it can be shown that they are bound not to do so by reference to a prohibition in either treaty law or customary international law. Support for this contention was found in dicta of the Permanent Court of International Justice in the "Lotus" case that "restrictions upon the independence of States cannot ... be presumed" and that international law leaves to States "a wide measure of discretion which is only limited in certain cases by prohibitive rules" (P.C.I.J., Series A, No. 10, pp. 18 and 19). Reliance was also placed on the dictum of the present Court in the case concerning Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America) 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" (I.C.J. Reports 1986, p. 135, para. 269).

For other States, the invocation of these dicta in the "Lotus" case was inapposite; their status in contemporary international law and applicability in the very different circumstances of the present case were challenged. It was also contended that the above-mentioned dictum of the present Court was directed to the possession of armaments and was irrelevant to the threat or use of nuclear weapons.

Finally, it was suggested that, were the Court to answer the question put by the Assembly, the word "permitted" should be replaced by "prohibited".
22. The Court notes that 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 (see below, paragraph 86), as did the other States which took part in the proceedings.
Hence, the argument concerning the legal conclusions to be drawn from the use of the word "permitted", and the questions of burden of proof to which it was said to give rise, are without particular significance for the disposition of the issues before the Court.

[p. 263] 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.

[pp. 271-272 Decl. Bedjaoui] 15. Thus the Court, in this Opinion, is far more circumspect than its predecessor in the "Lotus " case in asserting today that what is not expressly prohibited by international law is not therefore authorized.
16. While not finding either in favour of or against the legality of the threat or use of nuclear weapons, the Court takes note, in its Opinion, of the existence of a very advanced process of change in the relevant international law or, in other words, of a current trend towards the replacement of one rule of international law by another, where the first is already defunct and its successor does not yet exist. Once again, if the Court as a judicial body felt that it could do no more than register this fact, States should not, in my view, see in this any authorization whatever to act as they please.

[pp. 279-280 Decl. Vereshchetin] However, I find myself obliged to explain the reasons which have led me to vote in favour of paragraph 2 E of the dispositif, which carries the implication of the indecisiveness of the Court and indirectly admits the existence of a "grey area" in the present regulation of the matter.
The proponents of the view that a court should be prohibited from declaring non liquet regard this prohibition as a corollary of the concept of the "completeness" of the legal system. Those among their number who do not deny the existence of gaps in substantive international law consider that it is the obligation of the Court in a concrete case to fill the gap and thus, by reference to a general legal principle or by way of judicial law-creation, to provide for the "completeness" of the legal system.

On the other hand, there is a strong doctrinal view that the alleged "prohibition" on a declaration of a non liquet "may not be fully sustained by any evidence yet offered" (J. Stone, "Non Liquet and the Function of Law in the International Community", The British Year Book of International Law, 1959, p. 145). In his book devoted specifically to the problems of lacunae in international law, L. Siorat comes to the conclusion that in certain cases a court is obliged to declare a non liquet (Le problème des lacunes en droit international, 1958, p. 189).

In critically assessing the importance for our case of the doctrinal debate on the issue of non liquet, one cannot lose sight of the fact that the debate has concerned predominantly, if not exclusively, the admissibility or otherwise of non liquet in a contentious procedure in which the Court is called upon to pronounce a binding, definite decision settling the dispute between the parties. Even in those cases, the possibility of declaring a non liquet was not excluded by certain authoritative publicists, although this view could not be convincingly supported by arbitral and judicial practice.

In the present case, however, the Court is engaged in advisory procedure. It is requested not to resolve an actual dispute between actual parties, but to state the law as it finds it at the present stage of its development. Nothing in the question put to the Court or in the written and oral pleadings by the States before it can be interpreted as a request to fill the gaps, should any be found, in the present status of the law on the matter. On the contrary, several States specifically stated that the Court "is not being asked to be a legislator, or to fashion a régime for nuclear disarmament" (Samoa, CR 95/31, p. 34) and that "[t]he Court would be neither speculating nor legislating, but elucidating the law as it exists and is understood by it ..." (Egypt, CR95/23, pp. 32-33; see also the oral statement of Malaysia, CR95/27, p. 52.)

Even had the Court been asked to fill the gaps, it would have had to refuse to assume the burden of law-creation, which in general should not be the function of the Court. In advisory procedure, where the Court finds a lacuna in the law or finds the law to be imperfect, it ought merely to state this without trying to fill the lacuna or improve the law by way of judicial legislation. The Court cannot be blamed for indecisiveness or evasiveness where the law, upon which it is called to pronounce, is itself inconclusive. Even less warranted would be any allegation of the Court's indecisiveness or evasiveness in this particular Opinion, which gives an unequivocal, albeit non-exhaustive, answer to the question put to the Court.

[p. 291 S.O. Guillaume] ] 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.
10. International law rests on the principle of the sovereignty of States and thus originates from their consent. In other words, in the excellent language of the Permanent Court, "international law governs relations between independent States. The rules of law binding upon States therefore emanate from their own free will." ("Lotus", Judgment No. 9, 1927, P.C.I.J., Series A, No. 10, p. 18.)

[p. 322 D.O. Schwebel] The just-quoted first paragraph of paragraph 2 E of the holdings is followed by the Court's ultimate, paramount - and sharply controverted - conclusion in the case, narrowly adopted by the President's casting vote:

"However, 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."

This is an astounding conclusion to be reached by the International Court of Justice. Despite the fact that its Statute "forms an integral part" of the United Nations Charter, and despite the comprehensive and categorical terms of Article 2, paragraph 4, and Article 51 of that Charter, the Court concludes on the supreme issue of the threat or use of force of our age that it has no opinion. In an extreme circumstance of self-defence, in which the very survival of a State would be at stake", the Court finds that international law and hence the Court have nothing to say. After many months of agonizing appraisal of the law, the Court discovers that there is none. When it comes to the supreme interests of State, the Court discards the legal progress of the twentieth century, puts aside the provisions of the Charter of the United Nations of which it is "the principal judicial organ", and proclaims, in terms redolent of Realpolitik, its ambivalence about the most important provisions of modern international law. If this was to be its ultimate holding, the Court would have done better to have drawn on its undoubted discretion not to render an opinion at all.

Neither predominant legal theory (as most, definitively developed by Lauterpacht in The Function of Law in the International Community, 1933) nor the precedent of this Court admit a holding of non liquet, still less a holding - or inability to hold - of such a fundamental character.

[pp. 389-390 D.O. Shahabuddeen] The commentators suggest that some decisions of the Court could be understood as implying a non liquet. It is possible that the second part of subparagraph E of paragraph 2 of the operative paragraph of the Court's Advisory Opinion will be similarly interpreted. If that is the correct interpretation, I respectfully differ from the position taken by the Court.

To attract the idea of a non liquet in this case, it would have to be shown that there is a gap in the applicability of whatever may be the correct principles regulating the question as to the circumstances in which a State may be considered as having or as not having a right to act.

If, as it is said, international law has nothing to say on the subject of the legality of the use of nuclear weapons, this necessarily means that international law does not include a rule prohibiting such use. On the received view of the "Lotus" decision, absent such a prohibitory rule, States have a right to use nuclear weapons.

On the other hand, if that view of "Lotus" is incorrect or inadequate in the light of subsequent changes in the international legal structure, then the position is that States have no right to use such weapons unless international law authorizes such use. If international law has nothing to say on the subject of the use of nuclear weapons, this necessarily means that international law does not include a rule authorizing such use. Absent such authorization, States do not have a right to use nuclear weapons.

It follows that, so far as this case at any rate is concerned, the principle on which the Court acts, be it one of prohibition or one of authorization, leaves no room unoccupied by law and consequently no space available to be filled by the non liquet doctrine or by arguments traceable to it. The fact that these are advisory proceedings and not contentious ones makes no difference; the law to be applied is the same in both cases.

[pp. 393-394 D.O. Shahabuddeen] Thus, however far-reaching may be the rights conferred by sovereignty, those rights cannot extend beyond the framework within which sovereignty itself exists; in particular, they cannot violate the framework. The framework shuts out the right of a State to embark on a course of action which would dismantle the basis of the framework by putting an end to civilization and annihilating mankind. It is not that a State is prohibited from exercising a right which, but for the prohibition, it would have; a State can have no such right to begin with.
So a prior question in this case is this: even if there is no prohibition, is there anything in the sovereignty of a State which would entitle it to embark on a course of action which could effectively wipe out the existence of all States by ending civilization and annihilating mankind? An affirmative answer is not reasonable; that sovereignty could. not include such a right is suggested by the fact that the acting State would be one of what the Permanent Court of International Justice, in the language of the times, referred to as "co-existing independent communities", with a consequential duty to respect the sovereignty of other States. It is, difficult for the Court to uphold a proposition that, absent a prohibition, a State has a right in law to act in ways which could deprive the sovereignty of all other States of meaning.

[p. 426 D.O. Shahabuddeen] The implication of that part of the Court's holding is that, in the view of the Court, it is possible that the use of nuclear weapons could be lawful "in an extreme circumstance of self-defence, in which the very survival of a State would be at stake", and hence even if humanitarian law would otherwise be violated. What the Court so sought to leave on the basis of a possibility takes on a firmer aspect in the light of the "Lotus" case, as ... generally understood. In saying that it cannot definitively decide, the Court is saying that it cannot definitively say whether or not a prohibitory rule exists. If the Court is in a position in which it cannot definitively say whether or not a prohibitory rule exists, the argument can be made that, on the basis of that case, the presumption is in favour of the right of States to act unrestrained by any such rule. Accordingly, the meaning of the Court's position would be that States have a right in law to use nuclear weapons. If this was not the intended result, the Court's holding was not well conceived.

[p. 435 D.O. Weeramantry] (ii) Paragraph 2 E - (7 votes to 7. Casting vote in favour by the President)
I am in fundamental disagreement with both sentences contained within this paragraph.
I strongly oppose the presence of the word "generally" in the first sentence. The word is too uncertain in content for use in an Advisory Opinion, and I cannot assent to a proposition which, even by remotest implication, leaves open any possibility that the use of nuclear weapons would not be contrary to law in any circumstances whatsoever. I regret the presence of this word in a sentence which otherwise states the law correctly. It would also appear that the word "generally" introduces an element of internal contradiction into the Court's Opinion, for in paragraphs 2 C and 2 D of the Court's Opinion, the Court concludes that nuclear weapons must be consistent with the United Nations Charter, the principles of international law, and the principles of humanitarian law, and, such consistency being impossible, the weapon becomes illegal.
The word "generally" admits of many meanings, ranging through various gradations, from "as a general rule; commonly", to "universally; with respect to all or nearly all"1. Even with the latter meaning, the word opens a window of permissibility, however narrow, which does not truly reflect the law. There should be no niche in the legal principle, within which a nation may seek refuge, constituting itself the sole judge in its own cause on so important a matter.

The main purpose of this opinion is to show that, not generally but always, the threat or use of nuclear weapons would be contrary to the rules of international law and, in particular, to the principles and rules of humanitarian law. Paragraph 2E should have been in those terms, and the Opinion need have stated no more.

[p. 493 D.O. Weeramantry] It is self-evident that no system of law can depend for its operation or development on specific prohibitions ipsissimis verbis. Any developed system of law has, in addition to its specific commands and prohibitions, an array of general principles which from time to time are applied to specific items of conduct or events which have not been the subject of an express ruling before. The general principle is then applied to the specific situation and out of that particular application a rule of greater specificity emerges.
A legal system based on the theory that what is not expressly prohibited is permitted would be a primitive system indeed, and international law has progressed far beyond this stage. Even if domestic systems could function on that basis, - which indeed is doubtful - international law, born of generations of philosophical thinking, cannot. Modern legal philosophy in many jurisdictions has exposed the untenability of this view in regard to domestic systems and, a fortiori, the same applies to international law.

[pp. 495-496 D.O. Weeramantry] In the half century that has elapsed since the "Lotus" case, is quite evident that international law - and the law relating to humanitarian conduct in war - have developed considerably, imposing additional restrictions on State sovereignty over and above those that existed at the time of the "Lotus" case. This Court's own jurisprudence in the Corfu Channel case sees customary international law as imposing a duty on all States so to conduct their affairs as not to injure others, even though there was no prohibition ipsissimis verbis of the particular act which constituted a violation of the complaining nation's rights. This Court cannot in 1996 construe "Lotus" so narrowly as to take the law ward in time even beyond the Martens Clause.

[pp. 557-558 D.O. Koroma] In my view, it is wholly incoherent in the light of the material before the Court to say that it cannot rule definitively on the matter now before it in view of the current state of the law and because of the elements of facts at its disposal, for neither the law nor the facts are so imprecise or inadequate as to prevent the Court from reaching a definitive conclusion on the matter. On the other hand, the Court's findings could be construed as suggesting either that there is a gap, a lacuna, in the existing law or that the Court is unable to reach a definitive conclusion on the matter because the law is imprecise or its content insufficient or that it simply does not exist. It does not appear to me any new principles are needed for a determination of the matter to be made. All that was requested of the Court was to apply the existing law. A finding of non liquet is wholly unfounded in the present case. The Court has always taken the view that the burden of establishing the law is on the Court and not on the Parties. The Court has stated that:

"there is no incompatibility with its judicial function in making a pronouncement on the rights and duties of the Parties under existing international law which would clearly be capable of having a forward reach ... The possibility of the law changing is ever present: but that cannot relieve the Court from its obligation to render a judgment on the basis of the law as it exists at the time of its decision ..." (Fisheries Jurisdiction, Merits, I.C.J. Reports 1974, p. 19, para. 40).

The corpus juris on the matter is not only considerable, but is sufficiently clear and precise for the Court to have been able to make a definitive finding. If the Court had applied the whole spectrum of the law, including international conventions, rules of customary international law, general principles of international law, judicial decisions, as well as resolutions of international organizations, there would have been no room for a purported finding of non liquet.

[p. 576 D.O. Koroma] On the other hand, the search for specific rules led the Court to overlook or not fully to apply the principles of the United Nations Charter when considering the question before it. One such principle that does not appear to have been given its due weight in the Judgment of the Court is Article 2, paragraph 1 of the Charter of the United Nations, which provides that "the Organization is based on the principle of sovereign equality of all its Members." The principle of sovereign equality of States is of general application. It presupposes respect for the sovereignty and territorial integrity of all States. International law recognizes the sovereignty of each State over its territory as well as the physical integrity of the civilian population. By virtue of this principle, a State is prohibited from inflicting injury or harm on another State. The principle is bound to be violated if nuclear weapons are used in a given conflict, because of their established and well-known characteristics. The use of such weapons would not only result in the violation of the territorial integrity of non-belligerent States by radioactive contamination, but would involve the death of thousands, if not millions, of the inhabitants of territories not parties to the conflict. This would be in violation of the principle as enshrined in the Charter, an aspect of the matter that would appear not to have been taken fully into consideration by the Court when making its findings.

[pp. 589-590 D.O. Higgins] 27. The meaning of the second sentence of paragraph 2 E of the dispositif, and thus what the two sentences of paragraph 2 E of the dispositif mean when taken together, is unclear. The second sentence is presumably not referring to self-defence in those exceptional circumstances, implied by the word "generally", that might allow a threat or use of nuclear weapons to be compatible with humanitarian law. If, as the Court has indicated in paragraph 42 (and operative paragraph 2 Q, the Charter law does not per se make a use of nuclear weapons illegal, and if a specific usecomplied with the provisions of Article 51 and was also compatible with humanitarian law, the Court can hardly be saying in the second sentence of paragraph 2 E that it knows not whether such a use would be lawful or unlawful.
28. Therefore it seems the Court is addressing the "general" circumstances that it envisages - namely that a threat or use of nuclear weapons violates humanitarian law - and that it is addressing whether in those circumstances a use of force in extremis and in conformity with Article 51 of the Charter. might nonetheless be regarded as lawful, or not. The Court answers that it does not know.
29. What the Court has done is reach a conclusion of "incompatibility in general" with humanitarian law; and then effectively pronounce a non liquet on whether a use of nuclear weapons in self-defence when the survival of a State is at issue might still be lawful, even were the particular use to be contrary to humanitarian law. Through this formula of non-pronouncement the Court necessarily leaves open the possibility that a use of nuclear weapons contrary to humanitarian law might nonetheless be lawful. This goes beyond anything that was claimed by the nuclear-weapon States appearing before the Court, who fully accepted that any lawful threat or use of nuclear weapons would have to comply with both the jus ad bellum and the jus in bello (see Advisory Opinion, para. 86).

30. That the formula chosen is a non liquet cannot be doubted, because the Court does not restrict itself to the inadequacy of facts and argument concerning the so-called "clean" and "precise" weapons. I share the Court's view that it has not been persuasively explained in what circumstances it might be essential to use any such weaponry. Nor indeed may it be assumed that such types of weapons (perhaps to be used against submarines, or in deserts) can suffice to represent for a nuclear-weapon State all that is required for an effective policy of deterrence.

31. The formula in the second part of paragraph 2 E refers also to "the current state of international law" as the basis for the Court's non liquet. I find it very hard to understand this reference. Paragraph F of the dispositif, and the final paragraphs of the Court's Opinion. indicate that the Court hopes for a negotiated and verified total disarmament, including nuclear disarmament. But - it cannot be the absence of this goal which means that international law has no answer to give on the use of nuclear weapons in self-defence. International law does not simply consist of total prohibitions. Nor can it be that there is no substantive law of self-defence upon which the Court may offer advice - this, all said and done, is one of the most well-developed areas of international law.

1The Shorter Oxford English Dictionary, 3rd ed., 1987, Vol. 1, p. 840.