The Principle of Proportionality

Proportionality, one of the basic principles of the Law of Armed Combat (LOAC), constrains the use of force in conflict. By acting as a guiding, general principle of LOAC, proportionality critically protects noncombatants by bounding the means and methods used during combat. While proportionality plays a role in the decision of whether or not to use military force, jus ad bellum, arguably its predominant function pertains to the conduct of hostilities once they begin, jus ad bello. This paper explores the role of proportionality as a principle of jus ad bello, or LOAC. This paper also explores two primary reasons for proportionality's weakness as a rule of law. The first is substantive in that proportionality implicitly grew from treaty, the Geneva Conventions, as a subset of another principle, discrimination. The second pertains to assessing proportionality.