THE PRINCIPLE OF PROPORTIONALITY IN THE LAW AND ETHICS OF WAR: STEPS TOWARD A UNIFIED VIEW OF PROPORTIONALITY IN JUS AD BELLUM AND JUS IN BELLO BY MOVING FROM SUBJECTIVE POLITICAL TO OBJECTIVE LEGAL CRITERIA

Proportionality is both a general principle of public international law and a legal term with many distinct meaning in different bodies of public international law. One body of public international law in which the concept of proportionality has an important general role, but which also has specific meaning for different purposes, is the international law of war. This general statement of the concept of proportionality in the law and ethics of war takes specific forms in the two broad subdivisions of the law and ethics of war: Jus ad Bellum and Jus in Bello. Proportionality governs the legality and legitimacy in using force and the conduct of hostilities in armed conflicts. Jus ad Bellum proportionality and Jus in Bello proportionality are separate principles, having long intellectual pedigree, incorporated into modern international law as general principle of law. However, proportionality presents many challenging questions due to the subjectivity in the judgment of proportionality. Proportionality has been transformed from a legal to political vehicle. One reason why proportionality is susceptible to politicization from a relatively clear, objectively measureable legal doctrine into justificatory, subjective political argument lies in the nature of proportionality itself. Invoking proportionality in law of war inevitably requires performing subjective analysis as states continue to legitimize its use of force. This is further complicated by the existing gap between the concept of Jus ad Bellum proportionality and Jus in Bello proportionality and between a principle of legality and rhetoric of political justification. Based on this complexity and ambiguity, this research provides arguments to restore legality, objectivity, and rule of law to proportionality by reinforcing the difference between Jus ad Bellum proportionality and Jus in Bello proportionality as well as proposing new approach to our understanding and application of proportionality in reality to prevent politicization of proportionality.