Use of Nuclear Weapons and the Doctrine of Self-Defense in International Law

Abstract

Article 51 of UN Charter permits States to use force for Self-defense as an exception to the customary international law prohibiting the states from using force for unreasonable purposes. Thus, International law recognizes self-defense and the same is acknowledged by International Court of Justice (ICJ) in Nicaragua Case on use of force. International law on self-defense has categorized the phenomenon into preventive and pre-emptive self-defense. Nonetheless, international law recognizes the pre-emptive nature of self-defense and does not recognizes the self-defense which is mere preventive in nature. Pre-emptive self-defense is anticipatory self-defense when a threat is imminent. Hence it is clear that international law allows only preemptive self - defense and not preventive self – defense. Validity of use of nuclear weapon vis-a-vis self-defense was examined by ICJ in the landmark international case Legality of the Treat or Use of Nuclear Weapons (1996). In this case the ICJ applied the concept of non liquet (no applicable law) and stated that there is no source of customary or treaty rules that expressly excludes the states from using nuclear weapons ,while it requires the states to fulfill the criteria for using self-defense. However, opinion of the court is divided and uncertain as to the application of international law for using force. However, the notion of use of force is limited to customary law requirement of concept of proportionality. It is the fundamental principle that unlimited use of force on the enemy should be proportionate to unlawful aggression. And the same principle reflected in Caroline case. The paper examines the existing sources relating to use of nuclear force for self-defense of states in International law with relevant international case laws. Contemporary issues relating to use of nuclear weapon with respect to self-defense is also discussed.