Practice Relating to Nuclear Weapons
Cameroon’s Instructor’s Manual (2006) states:
In its opinion of 8 July 1996 regarding the following question posed by the WHO and the UN General Assembly: “Is the threat or use of nuclear weapons in any circumstance permitted under international law?”, the ICJ said:
The radiation released by a nuclear explosion would affect health, agriculture, natural resources and demography over a very wide area. … The nuclear weapon has unique characteristics, in particular its destructive capacity, its capacity to cause untold human suffering, and its ability to cause damage to generations to come. 
Cameroon, Droit des conflits armés et droit international humanitaire, Manuel de l’instructeur en vigueur dans les forces de défense, Ministère de la Défense, Présidence de la République, Etat-major des Armées, 2006, p. 236, § 551.