From Jus Ad Bellum to Jus Contra Bellum: The Prohibition of the Use of Force in Normative and Institutional Perspective

Abstract

INTRODUCTION: THE SHIFT FROM JUS AD BELLUM TO JUS CONTRA BELLUM In Chapter I it was shown how the collective security system as it stands today developed primarily in response to the two devastating world wars. The anarchic international system where war was part of international politics (and regarded as an extension of a sovereign state's right to pursue the national interest), gave way to the liberal ideal of a collective security system based on respect for international law and institutions of collective security. Part of this shift away from power politics at international level involved a move away from what was known as the jus ad bellum , or the right that states would assert in order to use war in the national interest. The jus ad bellum was not limited by legal constraints to the extent that we have today in the Charter of the United Nations, and under customary international law. Ian Brownlie pointed out that in the period before 1914 (outbreak of the First World War) the right to resort to war was oft en asserted as a sovereign right. But even then statesmen and writers on the topic often linked the jus ad bellum to some or other justification, such as self-defence. By 1928, with the conclusion of the so-called Kellogg-Briand Pact (General Treaty for Renunciation of War as an Instrument of National Policy), the contracting parties declared that war would no longer be used as an instrument of national policy or to solve international disputes. This, according to Yoram Dinstein, was the historical moment when ‘international law progressed from jus ad bellum to jus contra bellum .’ In Chapter I the prohibition on the use of force was explained with reference to the theory and practice of the liberal ideal of collective security. The Security Council of the UN is the primary institutional guarantor of this ideal. The institutional framework designed to maintain international peace and security as discussed in Chapter I will serve as background to a discussion in Chapter II of the content of the prohibition of the use of force and the criminalisation of crimes against peace, which will be discussed in Chapter III.