World Court Ruling on the Legality of Nuclear Weapons
His determination and strong principles allowed him to stand firm in face of enormous political pressure from nuclear-armed states in the 1996 International Court of Justice ruling on the legality of nuclear weapons. The case considered whether or not nuclear bans should be banned in all circumstances as a matter of human rights. The Court ultimately found, to the disappointment of nuclear disarmers worldwide, that it could not conclude whether use of such weapons was illegal under all circumstances, although it did rule that there was an obligation on nations to negotiate nuclear disarmament. Weeramantry issued a dissenting opinion that use, or threat of use, of nuclear weapons under any circumstances was indeed against international law in.
"This Court, the principal judicial organ of the United Nations, must duly recognize the rights of future generations.
I regret that it has not held directly and categorically that the use or threat of use of nuclear weapons is unlawful in all circumstances without exception.
Two paragraphs of the Court’s Opinion state the law wrongly and incompletely, and I have therefore voted against them.
The use or threat of use of nuclear weapons is in my opinion incompatible with international law and its foundations.
It comforts me that these legal conclusions accord with what I see as the moralities of the matter and the interests of humanity.
Rationality, humanity and concern for the human future are built into the structure of international law."
Extracts from Judge Weeramantry’s Dissenting Opinion on nuclear weapons, International Court of Justice July 1997
On the specific question of whether usage of nuclear weapons in extreme circumstances of self-defence (such as the very survival of a State) might be lawful, the ICJ majority judgment indicated that it could not make a conclusive judgment about that. However, Weeramantry in his Dissenting Opinion, noted: “I have voted against this clause as I am of the view that the threat or use of nuclear weapons would not be lawful in any circumstances whatsoever, as it offends the fundamental principles of the jus in bello. This conclusion is clear and follows inexorably from well-established principles of international law.“
He noted that “all of the seven principles of humanitarian law discussed in this opinion apply to the use of nuclear weapons in self-defense, 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-defense 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”.
In subsequent years, Weeramantry continued to advocate the case against nuclear weapons, arguing in 2006 that “The bomb clearly stands categorically condemned by upwards of a dozen basic principles of international law…There cannot be one law for the nuclear powers and another law for the non-nuclear powers. By the very principles of law and justice which the powerful states seek to uphold, the nuclear weapon in any shape or form stands condemned. No policeman can enforce a law which the policeman himself openly violates” (Foreword to “Securing Our Survival: The Case for a Nuclear Weapons Convention, IALANA, INESP, IPPNW, 2007).
Ten years later, the principles that Weeramantry had long advocated were embodied in the 2017 UN Treaty on the Prohibition of Nuclear Weapons, now supported by an overwhelming majority of UN states.