Barbara Kwiatkowska
Professor of International Law
Deputy Director, Netherlands Institute for the Law of the Sea (NILOS)

The Five-Member Eritrea/Yemen Arbitral Tribunal - comprising Judges Sir Robert Jennings (President), Stephen M. Schwebel, Rosalyn Higgins, Ahmed S. El-Kosheri and Keith Highet - unanimously resolved in its two masterly Awards the disputed territorial sovereignty over the Red Sea islands (Phase I - 1998) and the delimitation of international maritime boundary (Phase II - 1999) in one of strategically most sensitive regions of the world.

The article surveys landmark progress marked by each of the Awards in the development of principles and rules of international law in the respective subject matters of the Awards. While due attention is paid to the consistency of the Awards with the preceding decisions of the International Court of Justice and arbitral tribunals concerning acquisition of territorial sovereignty and equitable maritime delimitation, distinct features - such as rejection by the 1998 Award of the existence of a principle of reversion of a newly independent state to the ancient title to territory - are also examined. The analysis of the 1999 Award focuses on the complex decision-making process which led the Arbitral Tribunal to equitable delimitation of the Eritrea/Yemen international maritime boundary by means of a single all-purpose boundary. The resultant line substantiates the governing role of equidistance between the opposite states and its adjustment by the factors pertaining to baselines, islands, reefs, low-tide elevations, strategic navigational concerns and interests of the third states concerned. The Tribunal also importantly reappraised the role of resource related factors and the principle of proportionality. Fisheries factors formed part of resolution of the territorial sovereignty in the 1998 Award, as further defined in the 1999 Award and as implemented through the subsequent cooperation of the parties. The article takes account of the multiple impacts of both Eritrea/Yemen Awards on the 2001 Qatar v. Bahrain (Merits) and the 2002 Cameroon v. Nigeria; Equatorial Guinea Intervening (Merits) Judgments as well as on the peaceful resolution of the Eritrea/Ethiopia Boundary dispute within the United Nations framework in 2002-2003.