This is the first post in our joint symposium arising out of the publication of the Chatham House report, Proportionality in the Conduct of Hostilities: The Incidental Harm Side of the Assessment. This piece is cross-posted on Just Security.
At the end of 2018 the International Law Programme at Chatham House published a report analysing the key steps in making assessments about proportionality under international humanitarian law, with a particular focus on incidental harm. The rule of proportionality as formulated in Article 51 of Additional Protocol I of 1977 (AP I) requires belligerents to refrain from attacks ‘which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated’.
The report addresses three sets of questions: first, the criteria of causation and foreseeability, the weight to be assigned to particular kinds of harm, and how to assess whether the expected incidental harm is excessive in relation to the anticipated military advantage; second, the types of incidental harm to be considered in proportionality assessments; and, third, a number of legal questions raised by the implementation of the rule in practice.
After putting the rule of proportionality into context, this blog post presents four of the points that the report seeks to clarify. These are: the causation of the incidental harm and whether it is foreseeable; ‘knock-on’ or ‘reverberating’ harm; the types of injury to civilians to be considered; and the notion of ‘excessive’ incidental harm. Read the rest of this entry…