Go to Home Page
  LIbrary Treaties International Court of Justice, Legality of Nuclear Weapons, July 8, 1996

Opinion of the International Court of Justice
on the Legality of Nuclear Weapons- Part II

60. Those States that believe that recourse to nuclear weapons is illegal stress that the conventions that include various rules providing for the limitation or elimination of nuclear weapons in certain areas (such as the Antarctic Treaty of 1959

Printer Friendly


which prohibits the deployment of nuclear weapons in the Antarctic, or the Treaty of Tlatelolco of 1967 which creates a nuclear-weapon-free zone in Latin America), or the conventions that apply certain measures of control and limitation to the existence of nuclear weapons (such as the 1963 Partial Test-Ban Treaty or the Treaty on the Non-Proliferation of Nuclear Weapons) all set limits to the use of nuclear weapons. In their view, these treaties bear witness, in their own way, to the emergence of a rule of complete legal prohibition of all uses of nuclear weapons.

61. Those States who defend the position that recourse to nuclear weapons is legal in certain circumstances see a logical contradiction in reaching such a conclusion. According to them, those Treaties, such as the Treaty on the Non-Proliferation of Nuclear Weapons, as well as Security Council resolutions 255 (1968) and 984 (1995) which take note of the security assurances given by the nuclear-weapon States to the non-nuclear-weapon States in relation to any nuclear aggression against the latter, cannot be understood as prohibiting the use of nuclear weapons, and such a claim is contrary to the very text of those instruments. For those who support the legality in certain circumstances of recourse to nuclear weapons, there is no absolute prohibition against the use of such weapons. The very logic and construction of the Treaty on the Non-Proliferation of Nuclear Weapons, they assert, confirm this. This Treaty, whereby, they contend, the possession of nuclear weapons by the five nuclear-weapon States has been accepted, cannot be seen as a treaty banning their use by those States; to accept the fact that those States possess nuclear weapons is tantamount to recognizing that such weapons may be used in certain circumstances. Nor, they contend, could the security assurances given by the nuclear-weapon States in 1968, and more recently in connection with the Review and Extension Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons in 1995, have been conceived without its being supposed that there were circumstances in which nuclear weapons could be used in a lawful manner. For those who defend the legality of the use, in certain circumstances, of nuclear weapons, the acceptance of those instruments by the different non-nuclear-weapon States confirms and reinforces the evident logic upon which those instruments are based.

62. The Court notes that the treaties dealing exclusively with acquisition, manufacture, possession, deployment and testing of nuclear weapons, without specifically addressing their threat or use, certainly point to an increasing concern in the international community with these weapons; the Court concludes from this that these treaties could therefore be seen as foreshadowing a future general prohibition of the use of such weapons, but they do not constitute such a prohibition by themselves. As to the treaties of Tlatelolco and Rarotonga and their Protocols, and also the declarations made in connection with the indefinite extension of the Treaty on the Non-Proliferation of Nuclear Weapons, it emerges from these instruments that: (a) a number of States have undertaken not to use nuclear weapons in specific zones (Latin America; the South Pacific) or against certain other States (non-nuclear-weapon States which are parties to the Treaty on the Non-Proliferation of Nuclear Weapons);

(b) nevertheless, even within this framework, the nuclear-weapon States have reserved the right to use nuclear weapons in certain circumstances; and

(c) these reservations met with no objection from the parties to the Tlatelolco or Rarotonga Treaties or from the Security Council.

63. These two treaties, the security assurances given in 1995 by the nuclear-weapon States and the fact that the Security Council took note of them with satisfaction, testify to a growing awareness of the need to liberate the community of States and the international public from the dangers resulting from the existence of nuclear weapons. The Court moreover notes the signing, even more recently, on 15 December 1995, at Bangkok, of a Treaty on the Southeast Asia Nuclear-Weapon-Free Zone, and on 11 April 1996, at Cairo, of a treaty on the creation of a nuclear-weapons-free zone in Africa. It does not, however, view these elements as amounting to a comprehensive and universal conventional prohibition on the use, or the threat of use, of those weapons as such.

64. The Court will now turn to an examination of customary international law to determine whether a prohibition of the threat or use of nuclear weapons as such flows from that source of law. As the Court has stated, the substance of that law must be "looked for primarily in the actual practice and opinio juris of States" (Continental Shelf (Libyan Arab Jamahiriya/Malta), Judgment, I.C.J. Reports 1985, p. 29, para. 27).

65. States which hold the view that the use of nuclear weapons is illegal have endeavoured to demonstrate the existence of a customary rule prohibiting this use. They refer to a consistent practice of non-utilization of nuclear weapons by States since 1945 and they would see in that practice the expression of an opinio juris on the part of those who possess such weapons.

66. Some other States, which assert the legality of the threat and use of nuclear weapons in certain circumstances, invoked the doctrine and practice of deterrence in support of their argument. They recall that they 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. In their view, if nuclear weapons have not been used since 1945, it is not on account of an existing or nascent custom but merely because circumstances that might justify their use have fortunately not arisen.

67. The Court does not intend to pronounce here upon the practice known as the "policy of deterrence". It notes that it is a fact that a number of States adhered to that practice during the greater part of the Cold War and continue to adhere to it. Furthermore, the Members of the international community are profoundly divided on the matter of whether non-recourse to nuclear weapons over the past fifty years constitutes the expression of an opinio juris. Under these circumstances the Court does not consider itself able to find that there is such an opinio juris.

68. According to certain States, the important series of General Assembly resolutions, beginning with resolution 1653 (XVI) of 24 November 1961, that deal with nuclear weapons and that affirm, with consistent regularity, the illegality of nuclear weapons, signify the existence of a rule of international customary law which prohibits recourse to those weapons. According to other States, however, the resolutions in question have no binding character on their own account and are not declaratory of any customary rule of prohibition of nuclear weapons; some of these States have also pointed out that this series of resolutions not only did not meet with the approval of all of the nuclear-weapon States but of many other States as well.

69. States which consider that the use of nuclear weapons is illegal indicated that those resolutions did not claim to create any new rules, but were confined to a confirmation of customary law relating to the prohibition of means or methods of warfare which, by their use, overstepped the bounds of what is permissible in the conduct of hostilities. In their view, the resolutions in question did no more than apply to nuclear weapons the existing rules of international law applicable in armed conflict; they were no more than the "envelope" or instrumentum containing certain pre-existing customary rules of international law. For those States it is accordingly of little importance that the instrumentum should have occasioned negative votes, which cannot have the effect of obliterating those customary rules which have been confirmed by treaty law.

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

71. Examined in their totality, the General Assembly resolutions put before the Court declare that the use of nuclear weapons would be "a direct violation of the Charter of the United Nations"; and in certain formulations that such use "should be prohibited". The focus of these resolutions has sometimes shifted to diverse related matters; however, several of the resolutions under consideration in the present case have been adopted with substantial numbers of negative votes and abstentions; thus, although those resolutions are a clear sign of deep concern regarding the problem of nuclear weapons, they still fall short of establishing the existence of an opinio juris on the illegality of the use of such weapons.

72. The Court further notes that the first of the resolutions of the General Assembly expressly proclaiming the illegality of the use of nuclear weapons, resolution 1653 (XVI) of 24 November 1961 (mentioned in subsequent resolutions), after referring to certain international declarations and binding agreements, from the Declaration of St. Petersburg of 1868 to the Geneva Protocol of 1925, proceeded to qualify the legal nature of nuclear weapons, determine their effects, and apply general rules of customary international law to nuclear weapons in particular. That application by the General Assembly of general rules of customary law to the particular case of nuclear weapons indicates that, in its view, there was no specific rule of customary law which prohibited the use of nuclear weapons; if such a rule had existed, the General Assembly could simply have referred to it and would not have needed to undertake such an exercise of legal qualification.

73. Having said this, the Court points out that the adoption each year by the General Assembly, by a large majority, of resolutions recalling the content of resolution 1653 (XVI), and requesting the member States to conclude a convention prohibiting the use of nuclear weapons in any circumstance, reveals the desire of a very large section of the international community to take, by a specific and express prohibition of the use of nuclear weapons, a significant step forward along the road to complete nuclear disarmament. The emergence, as lex lata, of a customary rule specifically prohibiting the use of nuclear weapons as such is hampered by the continuing tensions between the nascent opinio juris on the one hand, and the still strong adherence to the practice of deterrence on the other.

74. The Court not having found a conventional rule of general scope, nor a customary rule specifically proscribing the threat or use of nuclear weapons per se, it will now deal with the question whether recourse to nuclear weapons must be considered as illegal in the light of the principles and rules of international humanitarian law applicable in armed conflict and of the law of neutrality.

75. A large number of customary rules have been developed by the practice of States and are an integral part of the international law relevant to the question posed. The "laws and customs of war" as they were traditionally called were the subject of efforts at codification undertaken in The Hague (including the Conventions of 1899 and 1907), and were based partly upon the St. Petersburg Declaration of 1868 as well as the results of the Brussels Conference of 1874. This "Hague Law" and, more particularly, the Regulations Respecting the Laws and Customs of War on Land, fixed the rights and duties of belligerents in their conduct of operations and limited the choice of methods and means of injuring the enemy in an international armed conflict. One should add to this the "Geneva Law" (the Conventions of 1864, 1906, 1929 and 1949), which protects the victims of war and aims to provide safeguards for disabled armed forces personnel and persons not taking part in the hostilities. These two branches of the law applicable in armed conflict have become so closely interrelated that they are considered to have gradually formed one single complex system, known today as international humanitarian law. The provisions of the Additional Protocols of 1977 give expression and attest to the unity and complexity of that law.

76. Since the turn of the century, the appearance of new means of combat has without calling into question the longstanding principles and rules of international law rendered necessary some specific prohibitions of the use of certain weapons, such as explosive projectiles under 400 grammes, dum-dum bullets and asphyxiating gases. Chemical and bacteriological weapons were then prohibited by the 1925 Geneva Protocol. More recently, the use of weapons producing "non-detectable fragments", of other types of "mines, booby traps and other devices", and of "incendiary weapons", was either prohibited or limited, depending on the case, by the Convention of 10 October 1980 on Prohibitions or Restrictions on the Use of Certain Conventional Weapons Which May Be Deemed to Be Excessively Injurious or to Have Indiscriminate Effects. The provisions of the Convention on "mines, booby traps and other devices" have just been amended, on 3 May 1996, and now regulate in greater detail, for example, the use of anti-personnel land mines.

77. All this shows that the conduct of military operations is governed by a body of legal prescriptions. This is so because "the right of belligerents to adopt means of injuring the enemy is not unlimited" as stated in Article 22 of the 1907 Hague Regulations relating to the laws and customs of war on land. The St. Petersburg Declaration had already condemned the use of weapons "which uselessly aggravate the suffering of disabled men or make their death inevitable". The aforementioned Regulations relating to the laws and customs of war on land, annexed to the Hague Convention IV of 1907, prohibit the use of "arms, projectiles, or material calculated to cause unnecessary suffering" (Art. 23).

78. The cardinal principles contained in the texts constituting the fabric of humanitarian law are the following. The first is aimed at the protection of the civilian population and civilian objects and establishes the distinction between combatants and non-combatants; States must never make civilians the object of attack and must consequently never use weapons that are incapable of distinguishing between civilian and military targets. According to the second principle, it is prohibited to cause unnecessary suffering to combatants: it is accordingly prohibited to use weapons causing them such harm or uselessly aggravating their suffering. In application of that second principle, States do not have unlimited freedom of choice of means in the weapons they use.

The Court would likewise refer, in relation to these principles, to the Martens Clause, which was first included in the Hague Convention II with Respect to the Laws and Customs of War on Land of 1899 and which has proved to be an effective means of addressing the rapid evolution of military technology. A modern version of that clause is to be found in Article 1, paragraph 2, of Additional Protocol I of 1977, which reads as follows: "In cases not covered by this Protocol or by other inernational agreements, civilians and combatants remain under the protection and authority of the principles of international law derived from established custom, from the principles of humanity and from the dictates of public conscience."

In conformity with the aforementioned principles, humanitarian law, at a very early stage, prohibited certain types of weapons either because of their indiscriminate effect on combatants and civilians or because of the unnecessary suffering caused to combatants, that is to say, a harm greater than that unavoidable to achieve legitimate military objectives. If an envisaged use of weapons would not meet the requirements of humanitarian law, a threat to engage in such use would also be contrary to that law.

79. It is undoubtedly because a great many rules of humanitarian law applicable in armed conflict are so fundamental to the respect of the human person and "elementary considerations of humanity" as the Court put it in its Judgment of 9 April 1949 in the Corfu Channel case (I.C.J. Reports 1949, p. 22), that the Hague and Geneva Conventions have enjoyed a broad accession. Further these fundamental rules are to be observed by all States whether or not they have ratified the conventions that contain them, because they constitute intransgressible principles of international customary law.

80. The Nuremberg International Military Tribunal had already found in 1945 that the humanitarian rules included in the Regulations annexed to the Hague Convention IV of 1907 "were recognized by all civilized nations and were regarded as being declaratory of the laws and customs of war" (International Military Tribunal, Trial of the Major War Criminals, 14 November 1945 1 October 1946, Nuremberg, 1947, Vol. 1, p. 254).

81. The Report of the Secretary-General pursuant to paragraph 2 of Security Council resolution 808 (1993), with which he introduced the Statute of the International Tribunal for the Prosecution of Persons Responsible for Serious Violations of International Humanitarian Law Committed in the Territory of the Former Yugoslavia since 1991, and which was unanimously approved by the Security Council (resolution 827 (1993)), stated: "In the view of the Secretary-General, the application of the principle nullum crimen sine lege requires that the international tribunal should apply rules of international humanitarian law which are beyond any doubt part of customary law . . .

The part of conventional international humanitarian law which has beyond doubt become part of international customary law is the law applicable in armed conflict as embodied in: the Geneva Conventions of 12 August 1949 for the Protection of War Victims; the Hague Convention (IV) Respecting the Laws and Customs of War on Land and the Regulations annexed thereto of 18 October 1907; the Convention on the Prevention and Punishment of the Crime of Genocide of 9 December 1948; and the Charter of the International Military Tribunal of 8 August 1945."

82. The extensive codification of humanitarian law and the extent of the accession to the resultant treaties, as well as the fact that the denunciation clauses that existed in the codification instruments have never been used, have provided the international community with a corpus of treaty rules the great majority of which had already become customary and which reflected the most universally recognized humanitarian principles. These rules indicate the normal conduct and behaviour expected of States.

83. It has been maintained in these proceedings that these principles and rules of humanitarian law are part of jus cogens as defined in Article 53 of the Vienna Convention on the Law of Treaties of 23 May 1969. The question whether a norm is part of the jus cogens relates to the legal character of the norm. The request addressed to the Court by the General Assembly raises the question of the applicability of the principles and rules of humanitarian law in cases of recourse to nuclear weapons and the consequences of that applicability for the legality of recourse to these weapons. But it does not raise the question of the character of the humanitarian law which would apply to the use of nuclear weapons. There is, therefore, no need for the Court to pronounce on this matter.

84. Nor is there any need for the Court elaborate on the question of the applicability of Additional Protocol I of 1977 to nuclear weapons. It need only observe that while, at the Diplomatic Conference of 1974-1977, there was no substantive debate on the nuclear issue and no specific solution concerning this question was put forward, Additional Protocol I in no way replaced the general customary rules applicable to all means and methods of combat including nuclear weapons. In particular, the Court recalls that all States are bound by those rules in Additional Protocol I which, when adopted, were merely the expression of the pre-existing customary law, such as the Martens Clause, reaffirmed in the first article of Additional Protocol I. The fact that certain types of weapons were not specifically dealt with by the 1974-1977 Conference does not permit the drawing of any legal conclusions relating to the substantive issues which the use of such weapons would raise.

85. Turning now to the applicability of the principles and rules of humanitarian law to a possible threat or use of nuclear weapons, the Court notes that doubts in this respect have sometimes been voiced on the ground that these principles and rules had evolved prior to the invention of nuclear weapons and that the Conferences of Geneva of 1949 and 1974-1977 which respectively adopted the four Geneva Conventions of 1949 and the two Additional Protocols thereto did not deal with nuclear weapons specifically. Such views, however, are only held by a small minority. In the view of the vast majority of States as well as writers there can be no doubt as to the applicability of humanitarian law to nuclear weapons.

86. The Court shares that view. Indeed, nuclear weapons were invented after most of the principles and rules of humanitarian law applicable in armed conflict had already come into existence; the Conferences of 1949 and 1974-1977 left these weapons aside, and there is a qualitative as well as quantitative difference between nuclear weapons and all conventional arms. However, it cannot be concluded from this that the established principles and rules of humanitarian law applicable in armed conflict did not apply to nuclear weapons. Such a conclusion would be incompatible with the intrinsically humanitarian character of the legal principles in question which permeates the entire law of armed conflict and applies to all forms of warfare and to all kinds of weapons, those of the past, those of the present and those of the future. In this respect it seems significant that the thesis that the rules of humanitarian law do not apply to the new weaponry, because of the newness of the latter, has not been advocated in the present proceedings. On the contrary, the newness of nuclear weapons has been expressly rejected as an argument against the application to them of international humanitarian law:

"In general, international humanitarian law bears on the threat or use of nuclear weapons as it does of other weapons.

International humanitarian law has evolved to meet contemporary circumstances, and is not limited in its application to weaponry of an earlier time. The fundamental principles of this law endure: to mitigate and circumscribe the cruelty of war for humanitarian reasons." (New Zealand, Written Statement, p. 15, paras. 63-64.)

None of the statements made before the Court in any way advocated a freedom to use nuclear weapons without regard to humanitarian constraints. Quite the reverse; it has been explicitly stated,

"Restrictions set by the rules applicable to armed conflicts in respect of means and methods of warfare definitely also extend to nuclear weapons" (Russian Federation, CR 95/29, p. 52);

"So far as the customary law of war is concerned, the United Kingdom has always accepted that the use of nuclear weapons is subject to the general principles of the jus in bello" (United Kingdom, CR 95/34, p. 45); and

"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" (United States of America, CR 95/34, p. 85.)

87. Finally, the Court points to the Martens Clause, whose continuing existence and applicability is not to be doubted, as an affirmation that the principles and rules of humanitarian law apply to nuclear weapons.

88. The Court will now turn to the principle of neutrality which was raised by several States. In the context of the advisory proceedings brought before the Court by the WHO concerning the Legality of the Use by a State of Nuclear Weapons in Armed Conflict, the position was put as follows by one State:

"The principle of neutrality, in its classic sense, was aimed at preventing the incursion of belligerent forces into neutral territory, or attacks on the persons or ships of neutrals. Thus: 'the territory of neutral powers is inviolable' (Article 1 of the Hague Convention (V) Respecting the Rights and Duties of Neutral Powers and Persons in Case of War on Land, concluded on 18 October 1907); 'belligerents are bound to respect the sovereign rights of neutral powers . . .' (Article 1 to the Hague Convention (XIII) Respecting the Rights and Duties of Neutral Powers in Naval War, concluded on 18 October 1907), 'neutral states have equal interest in having their rights respected by belligerents . . .' (Preamble to Convention on Maritime Neutrality, concluded on 20 February 1928). It is clear, however, that the principle of neutrality applies with equal force to transborder incursions of armed forces and to the transborder damage caused to a neutral State by the use of a weapon in a belligerent State." (Legality of the Use by a State of Nuclear Weapons in Armed Conflict, Nauru, Written Statement (I), p. 35, IV E.)

The principle so circumscribed is presented as an established part of the customary international law.

89. The Court finds that as in the case of the principles of humanitarian law applicable in armed conflict, international law leaves no doubt that the principle of neutrality, whatever its content, which is of a fundamental character similar to that of the humanitarian principles and rules, is applicable (subject to the relevant provisions of the United Nations Charter), to all international armed conflict, whatever type of weapons might be used.

90. Although the applicability of the principles and rules of humanitarian law and of the principle of neutrality to nuclear weapons is hardly disputed, the conclusions to be drawn from this applicability are, on the other hand, controversial.

91. According to one point of view, the fact that recourse to nuclear weapons is subject to and regulated by the law of armed conflict does not necessarily mean that such recourse is as such prohibited. As one State put it to the Court:

"Assuming that a State's use of nuclear weapons meets the requirements of self-defence, it must then be considered whether it conforms to the fundamental principles of the law of armed conflict regulating the conduct of hostilities" (United Kingdom, Written Statement, p. 40, para. 3.44);

"the legality of the use of nuclear weapons must therefore be assessed in the light of the applicable principles of international law regarding the use of force and the conduct of hostilities, as is the case with other methods and means of warfare" (United Kingdom, Written Statement, p. 75, para. 4.2(3)); and

"The reality . . . is that nuclear weapons might be used in a wide variety of circumstances with very different results in terms of likely civilian casualties. In some cases, such as the use of a low yield nuclear weapon against warships on the High Seas or troops in sparsely populated areas, it is possible to envisage a nuclear attack which caused comparatively few civilian casualties. It is by no means the case that every use of nuclear weapons against a military objective would inevitably cause very great collateral civilian casualties." (United Kingdom, Written Statement, p. 53, para. 3.70; see also United States of America, Oral Statement, CR 95/34, pp. 89-90.)

92. Another view holds that recourse to nuclear weapons could never be compatible with the principles and rules of humanitarian law and is therefore prohibited. In the event of their use, nuclear weapons would in all circumstances be unable to draw any distinction between the civilian population and combatants, or between civilian objects and military objectives, and their effects, largely uncontrollable, could not be restricted, either in time or in space, to lawful military targets. Such weapons would kill and destroy in a necessarily indiscriminate manner, on account of the blast, heat and radiation occasioned by the nuclear explosion and the effects induced; and the number of casualties which would ensue would be enormous. The use of nuclear weapons would therefore be prohibited in any circumstance, notwithstanding the absence of any explicit conventional prohibition. That view lay at the basis of the assertions by certain States before the Court that nuclear weapons are by their nature illegal under customary international law, by virtue of the fundamental principle of humanity.

93. A similar view has been expressed with respect to the effects of the principle of neutrality. Like the principles and rules of humanitarian law, that principle has therefore been considered by some to rule out the use of a weapon the effects of which simply cannot be contained within the territories of the contending States.

94. The Court would observe that none of the States advocating the legality of the use of nuclear weapons under certain circumstances, including the "clean" use of smaller, low yield, tactical nuclear weapons, has indicated what, supposing such limited use were feasible, would be the precise circumstances justifying such use; nor whether such limited use would not tend to escalate into the all-out use of high yield nuclear weapons. This being so, the Court does not consider that it has a sufficient basis for a determination on the validity of this view.

95. Nor can the Court make a determination on the validity of the view that the recourse to nuclear weapons would be illegal in any circumstance owing to their inherent and total incompatibility with the law applicable in armed conflict. Certainly, as the Court has already indicated, the 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. Nevertheless, the Court considers that it does not have sufficient elements to enable it to conclude with certainty that the use of nuclear weapons would necessarily be at variance with the principles and rules of law applicable in armed conflict in any circumstance.

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-defence, in which its very survival would be at stake.

98. Given the eminently difficult issues that arise in applying the law on the use of force and above all the law applicable in armed conflict to nuclear weapons, the Court considers that it now needs to examine one further aspect of the question before it, seen in a broader context.

In the long run, international law, and with it the stability of the international order which it is intended to govern, are bound to suffer from the continuing difference of views with regard to the legal status of weapons as deadly as nuclear weapons. It is consequently important to put an end to this state of affairs: the long-promised complete nuclear disarmament appears to be the most appropriate means of achieving that result.

99. In these circumstances, the Court appreciates the full importance of the recognition by Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons of an obligation to negotiate in good faith a nuclear disarmament. This provision is worded as follows:

"Each of the Parties to the Treaty undertakes to pursue negotiations in good faith on effective measures relating to cessation of the nuclear arms race at an early date and to nuclear disarmament, and on a treaty on general and complete disarmament under strict and effective international control."

The legal import of that obligation goes beyond that of a mere obligation of conduct; the obligation involved here is an obligation to achieve a precise result nuclear disarmament in all its aspects by adopting a particular course of conduct, namely, the pursuit of negotiations on the matter in good faith.

100. This twofold obligation to pursue and to conclude negotiations formally concerns the 182 States parties to the Treaty on the Non-Proliferation of Nuclear Weapons, or, in other words, the vast majority of the international community.

Virtually the whole of this community appears moreover to have been involved when resolutions of the United Nations General Assembly concerning nuclear disarmament have repeatedly been unanimously adopted. Indeed, any realistic search for general and complete disarmament, especially nuclear disarmament, necessitates the co-operation of all States.

101. Even the very first General Assembly resolution, unanimously adopted on 24 January 1946 at the London session, set up a commission whose terms of reference included making specific proposals for, among other things, "the elimination from national armaments of atomic weapons and of all other major weapons adaptable to mass destruction". In a large number of subsequent resolutions, the General Assembly has reaffirmed the need for nuclear disarmament. Thus, in resolution 808 A (IX) of 4 November 1954, which was likewise unanimously adopted, it concluded

"that a further effort should be made to reach agreement on comprehensive and co-ordinated proposals to be embodied in a draft international disarmament convention providing for: . . . (b) The total prohibition of the use and manufacture of nuclear weapons and weapons of mass destruction of every type, together with the conversion of existing stocks of nuclear weapons for peaceful purposes."

The same conviction has been expressed outside the United Nations context in various instruments.

102. The obligation expressed in Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons includes its fulfilment in accordance with the basic principle of good faith. This basic principle is set forth in Article 2, paragraph 2, of the Charter. It was reflected in the Declaration on Friendly Relations between States (resolution 2625 (XXV) of 24 October 1970) and in the Final Act of the Helsinki Conference of 1 August 1975. It is also embodied in Article 26 of the Vienna Convention on the Law of Treaties of 23 May 1969, according to which "[e]very treaty in force is binding upon the parties to it and must be performed by them in good faith".

Nor has the Court omitted to draw attention to it, as follows:

"One of the basic principles governing the creation and performance of legal obligations, whatever their source, is the principle of good faith. Trust and confidence are inherent in international co-operation, in particular in an age when this co-operation in many fields is becoming increasingly essential." (Nuclear Tests (Australia v. France), Judgment of 20 December 1974, I.C.J. Reports 1974, p. 268, para. 46.)

103. In its resolution 984 (1995) dated 11 April 1995, the Security Council took care to reaffirm "the need for all States Parties to the Treaty on the Non-Proliferation of Nuclear Weapons to comply fully with all their obligations" and urged "all States, as provided for in Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons, to pursue negotiations in good faith on effective measures relating to nuclear disarmament and on a treaty on general and complete disarmament under strict and effective international control which remains a universal goal".

The importance of fulfilling the obligation expressed in Article VI of the Treaty on the Non-Proliferation of Nuclear Weapons was also reaffirmed in the final document of the Review and Extension Conference of the parties to the Treaty on the Non-Proliferation of Nuclear Weapons, held from 17 April to 12 May 1995.

In the view of the Court, it remains without any doubt an objective of vital importance to the whole of the international community today.

104. At the end of the present Opinion, the Court emphasizes that its reply to the question put to it by the General Assembly rests on the totality of the legal grounds set forth by the Court above (paragraphs 20 to 103), each of which is to be read in the light of the others. Some of these grounds are not such as to form the object of formal conclusions in the final paragraph of the Opinion; they nevertheless retain, in the view of the Court, all their importance.

105. For these reasons,

THE COURT,

(1) By thirteen votes to one, Decides to comply with the request for an advisory opinion;

IN FAVOUR: President Bedjaoui; Vice-President Schwebel; Judges Guillaume, Shahabuddeen, Weeramantry, Ranjeva, Herczegh, Shi, Fleischhauer, Koroma, Vereshchetin, Ferrari Bravo, Higgins;

AGAINST: Judge Oda.

(2) Replies in the following manner to the question put by the General Assembly:

A. Unanimously, There is in neither customary nor conventional international law any specific authorization of the threat or use of nuclear weapons;

B. By eleven votes to three, There is in neither customary nor conventional international law any comprehensive and universal prohibition of the threat or use of nuclear weapons as such;

IN FAVOUR: President Bedjaoui; Vice-President Schwebel; Judges Oda, Guillaume, Ranjeva, Herczegh, Shi, Fleischhauer, Vereshchetin, Ferrari Bravo, Higgins;

AGAINST: Judges Shahabuddeen, Weeramantry, Koroma.

C. Unanimously, A threat or use of force by means of nuclear weapons that is contrary to Article 2, paragraph 4, of the United Nations Charter and that fails to meet all the requirements of Article 51, is unlawful;

D. Unanimously, A threat or use of nuclear weapons should also be compatible with the requirements of the international law applicable in armed conflict, particularly those of the principles and rules of international humanitarian law, as well as with specific obligations under treaties and other undertakings which expressly deal with nuclear weapons;

E. By seven votes to seven, by the President's casting vote, It follows from the above-mentioned requirements that the threat or use of nuclear weapons would generally be contrary to the rules of international law applicable in armed conflict, and in particular the principles and rules of humanitarian law;

However, in view of the current state of international law, and 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;

IN FAVOUR: President Bedjaoui; Judges Ranjeva, Herczegh, Shi, Fleischhauer, Vereschetin, Ferrari Bravo;

AGAINST: Vice-President Schwebel; Judges Oda, Guillaume, Shahabuddeen, Weeramantry, Koroma, Higgins.

F. Unanimously, There exists an obligation to pursue in good faith and bring to a conclusion negotiations leading to nuclear disarmament in all its aspects under strict and effective international control.

Done in English and in French, the English text being authoritative, at the Peace Palace, The Hague, this eighth day of July, one thousand nine hundred and ninety-six, in two copies, one of which will be placed in the archives of the Court and the other transmitted to the Secretary-General of the United Nations.

(Signed) Mohammed BEDJAOUI, President.

(Signed) Eduardo VALENCIA-OSPINA, Registrar.

President BEDJAOUI, Judges HERCZEGH, SHI, VERESHCHETIN and FERRARI BRAVO append declarations to the Advisory Opinion of the Court.

Judges GUILLAUME, RANJEVA and FLEISCHHAUER append separate opinions to the Advisory Opinion of the Court.

Vice-President SCHWEBEL, Judges ODA, SHAHABUDDEEN, WEERAMANTRY, KOROMA and HIGGINS append dissenting opinions to the Advisory Opinion of the Court.

(Initialled) M. B.

(Initialled) E. V. O.

1 2