Соответствующая норма
Practice Relating to Rule 145. Reprisals
Section C. Proportionality of 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 … 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.