Specific restrictions placed on the warring party in the preparation of an attack.
An attack must be cancelled if it becomes apparent that it is of a type that is prohibited. If circumstances permit, an advance warning must be given for those attacks which may affect the civilian population. In determining the objective of an attack, and when a choice is possible, the one causing least danger to the civilian population must be selected. Furthermore, IHL requires those planning and deciding on an attack to take precautionary measures, including refraining from attacking when incidental loss of civilian life or destruction of civilian objects outweighs the military advantage of the attack.
The meaning of these obligations in practice remains controversial in many cases, mainly with regard to which precautions are “feasible”. Military and humanitarian considerations may influence the feasibility of such precautions: the importance and the urgency of destroying a target; the range, accuracy and effects radius of available weapons; the conditions affecting the accuracy of targeting; the proximity of civilians and civilian objects; the possible release of hazardous substances; the protection of the party’s own forces (and the proportionality between the additional protection for those forces and the additional risks for civilians and civilian objects when a certain means or method is chosen); the availability and feasibility of alternatives; the necessity to keep certain weapons available for future attacks on targets which are militarily more important or more risky for the civilian population.
See also Conduct of hostilities; Precautions against the effect of attacks;
- an attack must be cancelled if it becomes apparent that it is a prohibited one
- advance warning must be given, unless circumstances do not permit
- when a choice is possible, the objective causing the least danger to the civilian population must be selected
- additional obligations of those who plan or decide upon an attack: verify that objectives are not illicit, choose means and methods avoiding or minimizing civilian losses, refrain from attacks causing disproportionate civilian losses
DESGAGNÉ Richard, “The Prevention of Environmental Damage in Time of Armed Conflict: Proportionality and Precautionary Measures”, in YIHL, Vol. 3, 2000, pp. 109-129.
HENDERSON Ian, The Contemporary Law of Targeting: [Military Objectives, Proportionality and Precautions in Attack under Additional Protocol I], Leiden, Boston, M. Nijhoff, 2009, 266 pp.