ABSTRACT
The idea that military operations should not be disproportionately harmful is an essential element of just war theory, of which two versions are described. The orthodox conception rules out both the use of means for giving military advantage that are disproportionately harmful to enemy combatants and actions which are excessively costly in civilian casualties. A more recent revisionist view distinguishes the narrow proportionality of military actions against those liable to defensive harm, primarily unjust combatants, from the wide proportionality of acts that unintentionally harm innocents. These accounts are set in the context of some distinctive features of contemporary armed conflict.
