Attack Decision-Making

Proportionality is one of the most important civilian protection rules in the Law of Armed Conflict (LOAC). In an era when combat almost always occurs in areas with substantial civilian populations, the proportionality rule is critical to protecting civilians and civilian property from the incidental and collateral consequences of attacks directed at otherwise lawful targets. The proportionality rule, however, prohibits attacks against otherwise lawful military objectives only when the attacker anticipates that civilian casualties or destruction to civilian property will be excessive in relation to the concrete and direct military advantage anticipated from the attack. Application of the proportionality rule has triggered ongoing debates over the meaning of its constituent terms: What is a military advantage? How is military advantage to be valued? What qualifies as a concrete and direct advantage? When does the knowing infliction of civilian harm qualify as excessive? Considering criminal accountability adds another layer of complexity: What is the proper standard of assessing criminal responsibility based on a violation of this obligation? This chapter explores the relationship between the duty of obedience and the implementation of the proportionality obligation at the tactical level. Given that deliberate attack planning and dynamic targeting arise in different operational contexts, each requires a different implementation focus.