This is the final 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.
The new research paper published by Chatham House on Proportionality in the Conduct of Hostilities is a rigorous and thoughtful exposition of the civilian side of the notion of proportionality under international humanitarian law (IHL). This brief post focuses on three points that are raised by the paper: first, the way in which certain difficult questions concerning the reach of proportionality considerations are addressed; second, the question of the status of the natural environment; and third, the potential impact of the paper.
The proportionality calculus calls for a comparison of the expected incidental harm to civilians caused by an attack and the concrete and direct military advantage anticipated. Amongst the many difficult questions that arise from this formulation is the reach of the test, e.g. what type of harm is included, psychological or only physical harm? When might harm be considered as having been ‘caused’ by an attack? Does it include so-called ‘reverberating’ harm, manifesting sometime after an attack (as in the case with unexploded cluster sub-munitions)?
The research paper addresses this question of the reach of the proportionality analysis through the dual test of admissibility and weight. This has the significant advantage of offering a more nuanced way of dealing with some of these complicated questions concerning the scope of the proportionality analysis. For example, on the question of reverberating harm, the paper takes the position that ‘the geographic or temporal proximity of the harm to the attack is not determinative’ and should not affect the admissibility of reverberating harm (para 63). Instead, ‘[f]actors such as the passage of time between the attack and the injury, or the number of causal steps between one and the other, may affect the likelihood of the harm occurring and thus the weight to be assigned to it’ (para 64). That reverberating harm, manifesting sometime after an attack rather than at the time of the attack, must be taken into account in assessing proportionality must be right – there is nothing in the Additional Protocol I (API) formulation of the proportionality test that suggests excluding such types of harm. The reference in API is simply to an ‘attack which may be expected to cause incidental’ civilian harm – as the paper states, harm is caused by an attack if, ‘but for’ the attack, the harm would not occur (para 45), regardless of any proximity considerations. Instead, the proximity of expected harm to the attack might be relevant to the weight to be given to that potential harm. Read the rest of this entry…