Disputed territories and the law on the use of force: lessons from the Eritrea-Ethiopia case

On 19 December 2005, in its partial award, the Eritrea-Ethiopia Claims Commission found that Eritrea had acted in violation of the rules of international law on the use of force (jus ad bellum) in resorting to armed force to attack and occupy the disputed border town of Badme and surrounding areas, which were then under the administration of Ethiopia. In its award, the Claims Commission made a number of important findings which, taken with the Eritrea-Ethiopia Boundary Commission’s 2002 decision on boundary delimitation, contribute towards informing and clarifying the substance of international law applicable to disputed territories and the legal obligations of states acting in those areas, especially where the use of force is engaged. This article examines the Claims Commission’s jus ad bellum award and concentrates on three key issues: (a) the legality in international law of the resort to force as a means of gaining control over territory to which a state has (or believes that it has) a valid sovereign title; (b) the specific contours of self-defence in relation to territorial sovereignty claims, and (c) the legitimacy of dealing with use of force issues by arbitral tribunals. In September 2018, the leaders of the two countries signed a peace and friendship agreement, thus, setting course for a new era of peace and cooperation. The lessons that ought to be learnt by these two neighbouring countries and other states have been articulated as concluding remarks.