Thin or Thick? The Principle of Proportionality and International Humanitarian Law

Proportionality, as a concept, does not contain any inherent standards, but rather refers to a proper balance between all relevant factors. It is nevertheless necessary to make analytical distinctions that help identify the premises of its application within different contexts. This is particularly true for an area like international humanitarian law in which a proper focusing of the principle of proportionality is crucial. This article suggests that the distinction between a “thin” and a “thick” approach is a helpful analytical tool depending on the number and the character of factors to be taken into account in the application of the principle of proportionality. The judgment of the Supreme Court of Israel on the permissibility of “targeted killings” is used to exemplify the drawbacks and advantages of both approaches.