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UBC Theses and Dissertations

Lines at sea : why do states resolve their maritime boundary disputes? Østhagen, Andreas


This doctoral thesis was written in the period 2015–2019 at the University of British Columbia, Vancouver. It asks: Why are half the world’s maritime boundaries unresolved? How do states delineate such ownership and rights at sea? What does this tell us about international politics concerning the ocean? Boundaries in the ocean are man-made constructs of importance to everything from oil and gas production, to fisheries and environmental protection. By examining a relatively straightforward and simple question – why do some states settle their maritime boundary disputes whereas others do not? – we can find the factors that underpin dispute settlement at sea. This doctoral thesis draws on theories and assumptions within both international relations and international law. Employing a previously compiled dataset of 184 maritime boundaries, as well as in-depth analyses of 33 boundaries across four countries – Australia, Canada, Colombia, Norway – I identify the conditions and the causal factors that motivate and enable the resolution of maritime boundary disputes. I have found it insufficient to study maritime boundary disputes only as individual cases: they must be seen as interdependent complexes. Further, we must conceive of the dependent variable beyond the binary option of settled/not settled. By depicting the outcome as multi-step fluid processes, we can better understand the nuances concerning what drives and what hinders settlement of maritime boundary disputes, at various points in that process. This, in turn, allows a re-think of how states approach maritime space more generally, at a time when oceans are receiving greater political attention. Beyond relative power concerns and security considerations, states’ concern for legal precedent and the increasing engagement of domestic actors in settlement processes confirms the importance of taking a wider approach, acknowledging several layers of foreign policy-making. This thesis also makes an argument for an ongoing ‘territorialisation’ of ocean space and certain trends that might make maritime boundaries more important for society, and thus also more difficult for states to agree on.

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