Unilateral Port State Jurisdiction: The Quest for Universality in the Prevention, Reduction and Control of Ship-Source Pollution

The capacity to act as a port state in international law is best described by the specific powers exercised over foreign ships, namely inspection, detention, expulsion or request of any type of information prior to the entry into the port. Many of these powers are explicitly attributed to the state in multilateral instruments, whereby the flag state consents to having its ships subject to the jurisdiction of the port state. Notwithstanding the consensus around the complementary nature of port state jurisdiction with respect to certain obligations of the flag state, the port state is not limited to fulfil a secondary role. This is especially visible in the prevention, reduction and control of ship-source pollution, where some port states have not hesitated in acting regardless of an expressed consent by the flag state to the rule or standard being applied with the support of port powers. Not only do port states use more stringent enforcement powers to ensure that international treaties are effective, but they also prescribe novel rules and standards upon any foreign ship that approaches the port, often as a means of breaking an international negotiation deadlock. This study discusses the international legal basis for such unilateral jurisdiction by analysing the principles of state jurisdiction under the dichotomy parochial/cosmopolitan. By interpreting the stated and implicit purposes of port state actions under that dichotomy, this study proposes that states are finding a legal ground to act based on certain legal functions they fulfil in the international legal order. This argument puts into perspective the assumed self-sufficiency of territoriality and shows how unilateralism may also serve to seek to set universally applicable norms.