Related Rule
India
Practice Relating to Rule 145. Reprisals
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, India stated:
Reprisals or retaliation under international law are also governed by certain specific principles. First, reprisals to be valid and admissible could only be taken in response to a prior delict or wrongful act by a State … In other words, a nuclear weapon could not be used by way of reprisal against another State if that State did not commit any wrongful act or delict involving use of force. 
India, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, p. 2.
After pointing out the principle of proportionality and the obligation to respect “certain fundamental principles of humanitarian law”, India stated:
In view of the above, use of nuclear weapons even by way of reprisal or retaliation, appears to be unlawful. In any case, if the wrongful use of force in the first instance did not involve the use of nuclear weapons, it is beyond doubt that even in response by way of retaliation States do not have the right to use nuclear weapons because of their special quality as weapons of mass destruction. 
India, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, pp. 2–3.
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, India stated:
Reprisals or retaliation under international law are also governed by certain specific principles … Reprisals must remain within reasonable bounds of proportionality to the effect created by the original wrongful act … In other words … when a State commits … a wrongful act or delict, the use of force by way of reprisal would have to be proportionate and as such if the wrongful act did not involve the use of a nuclear weapon, the reprisal could also not involve the use of a nuclear weapon … In view of the above, use of nuclear weapons, even by way of reprisal or retaliation, appears to be unlawful. In any case, if the wrongful use of force in the first instance did not involve the use of nuclear weapons, it is beyond doubt that even in response by way of retaliation States do not have the right to use nuclear weapons because of their special quality as weapons of mass destruction. 
India, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, p. 2.
In its written statement submitted to the ICJ in the Nuclear Weapons case in 1995, India cited G. Fitzmaurice and stated:
Reprisals or retaliation under international law are also governed by certain specific principles … Reprisals could not involve acts which are malum in se such as certain violations of human rights, certain breaches of the laws of war and rules in the nature of ius cogens, that is to say obligations of an absolute character compliance with which is not dependent on corresponding compliance by others but is requisite in all circumstances unless under stress of literal vis major … In other words … even where a wrongful act involved the use of a nuclear weapon the reprisal action cannot involve [the] use of a nuclear weapon without violating certain fundamental principles of humanitarian law. In this sense, prohibition of the use of a nuclear weapon in an armed conflict is an absolute one, compliance with which is not dependent on corresponding compliance by others but is a requisite in all circumstances. In view of the above, [the] use of nuclear weapons even by way of reprisal or retaliation, appears to be unlawful. 
India, Written statement submitted to the ICJ, Nuclear Weapons case, 20 June 1995, p. 2.