TERRITORIAL BORDERS ON THE Arabian Peninsula have long been the source of bitter disagreements. The peninsular states - Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, the United Arab Emirates, and Yemen - have periodically challenged their respective frontiers. Though disagreements over territorial demarcations simmered among the peninsular states for decades, in the aftermath of the 1990-1 Gulf War, challenges to the status quo intensified, with competing claims dramatically thrust onto the regional political agenda. The purpose of this article is to examine and explain the almost simultaneous ignition of brush fires all along the international frontiers on the Arabian Peninsula.At one extreme, resolution to outstanding border disputes was pursued violently. For example, armed confrontations occurred in 1992 and 1994 along the border between Saudi Arabia and Qatar, and in 1995, 1997, and 1998 between Saudi Arabia and Yemen. At the other extreme, competing territorial claims were hurriedly accommodated. For example, after ten years of negotiations to define their respective borders, Oman and Yemen eventually reached a preliminary settlement in 1992, and a final agreement in 1997. Between these extremes was much posturing and bargaining. The point is that, whether through armed conflict or diplomatic agreement, after years of inertia territorial issues were confronted with a heightened sense of urgency in the wake of war.NEW INTEREST IN OLD DISPUTES: CASES AND THEMESThe question of international frontiers on and near the Arabian Peninsula took on great saliency because the competition for economic resources and the search for political identity were complicated by the absence of a viable regional arrangement for security. In the early 1990s, various peninsular states accelerated their efforts to explore and develop oil reserves near politically sensitive boundaries, in part to offset a flat international market and the 'maturation of older fields.'(f.1) Most important, the Gulf War of 1991 was a catalyst that brought into sharp focus new political realities. Old tensions were exacerbated and new territorial understandings were pursed vigorously as the logic of territoriality gained potency in the political climate of 'self-definition and self-assertion.'(f.2) The new interest paid to old disputes was further intensified by the lack of an effective institutional mechanism by which to accommodate divergent claims, as is clearly demonstrated by comparing five on-going and three newly resolved territorial contests on and near the Arabian Peninsula. The complexity of tripartite frontiers that are 'resolved' only through bilateral agreements is addressed.(f.3)In the comparative analysis of the eight cases, three factors are addressed: historical lineage, contested issues, and mediators. The basis for progress in the disputes that have been resolved through interstate negotiations is also explored and the similarities are emphasized so as to allow more general patterns to emerge from the territorial challenges made by the states in the region, though differences are acknowledged. The eight disputes involve the following sets of actors: - Saudi Arabia and Qatar, over approximately fifteen miles of territory; - Saudi Arabia and Yemen, over land near the old division of North and South Yemen; - Iran and the United Arab Emirates, over the islands of Abu Musa and the Tunbs; - Bahrain and Qatar, over the Hawar Islands and surrounding reefs; - Iraq and Kuwait, over the islands of Warba and Bubiyan, and Umm al Qasr; - Oman and Yemen (finalized in May 1997); - Oman and the United Arab Emirates (settled in April 1993); and - Saudi Arabia and Oman (finalized in 1995).Individually, some of these disputes appear relatively insignificant; however, against the backdrop of regional and peninsular politics since the end of the Gulf War, they assume much more significance, and the status of international boundaries for future relations among the Arabian Peninsula countries is painted in starker colours. …