Introduction
While the meaning of maritime security is subject to different understandings, it undoubtedly includes an interstate dimension concerned with overlapping entitlement to maritime space.
Clarity, certainty and predictability in maritime entitlement and jurisdiction, established in accordance with the “constitution” for the oceans – the 1982 UN Convention on the Law of the Sea (UNCLOS) – is the foundation for a rule-based order at sea. The lack of jurisdictional clarity can impede efficient utilisation of maritime resources, result in skirmishes between law enforcement or naval authorities of claimant states in disputed areas, and is viewed as a threat to national maritime security. It also poses impediments to effective national or regional action vis-à-vis traditional maritime security threats including piracy and armed robbery at sea, terrorism, illegal, unreported and unlicensed (IUU) fishing, and other maritime crime. Moreover, maritime disputes undermine inter- and extraregional relations and weaken any promise of collective action against ecosystem degradation and biodiversity loss on a global scale. Unsurprisingly, demarcation of maritime limits is considered “an essential precursor to the full resource potential of national maritime zones and the peaceful management of the oceans.”
For Southeast Asian states (consisting of the ten member states of the Association of Southeast Asian Nations [ASEAN] and Timor-Leste, who is on track to be the 11th member), sovereignty disputes coupled with congested coastal geography, deeply indented gulfs, and coastal areas scattered with small offshore features have resulted in overlapping claims to maritime entitlement that have not arisen in more diffuse regions like the Southwest and Central Pacific Ocean. While Southeast Asia has been described as a “scene of very active and innovative ocean boundary diplomacy” and some level of maritime jurisdictional clarity has been attained, there remain pockets of maritime areas that are subject to overlapping claims. While the territorial and maritime disputes in the South China Sea are perceived as the most contentious (particularly due to the involvement of extraregional actors such as China and Taiwan), there are also undelimited maritime areas between Southeast Asian states themselves and between Southeast Asian states and extraregional states (such as India, Palau, China and Australia) outside the South China Sea. These underlying interstate maritime entitlement and delimitation disputes manifest differently with varying degrees of gravity, from diplomatic protests to skirmishes between naval and coast guard authorities, all of which have consequences for maritime security in Southeast Asia.
Adding another potential layer of jurisdictional complexity is sea level rise (SLR) caused by ocean thermal expansion and ice sheet melt attributable to exponential increases in greenhouse gas (GHG) emissions. The most recent projection by the Intergovernmental Panel on Climate Change (IPCC) states that it is virtually certain that global mean sea level rise will continue to rise over the 21st century; the likely global sea level rise by 2100 is 0.15 – 0.23 m under a low GHG emissions scenario, and 0.20 – 0.29 m under a very high GHG scenario. While there are regional variations in SLR, Southeast Asia is one of the most vulnerable regions to SLR due to the concentration of activities along the region’s low-lying coastal areas, high population, and landmass. All Southeast Asian states are coastal states except for landlocked Laos, and two of these (the Philippines and Indonesia) are the world’s largest archipelagic states. Moreover, recent studies indicate that Southeast Asian coastal cities are sinking the fastest globally and this will amplify the impacts of SLR.
SLR presents a whole gamut of destructive consequences including coastal erosion, storm surges, saltwater intrusion, loss of mangrove forests, the destruction of coastal facilities, displacement of populations, risks to marine ecosystems and concomitant impacts on living resources and food security, and most extreme, loss of territory. All of these consequences have implications for multiple aspects of maritime security. However, it is the alteration of the physical configuration of coasts and consequent effects on unilateral limits (baselines and outer limits of maritime zones) and maritime boundaries that has the most significant repercussions for maritime jurisdictional clarity in Southeast Asia. UNCLOS, negotiated before climate change became a serious global problem, does not explicitly mention climate change or sea level rise and with one exception, has no express rules on consequences to unilateral limits and maritime boundaries in the event of climate changeinduced SLR. A central question is to what extent UNCLOS addresses the impact of SLR on unilateral maritime limits and maritime boundaries. Pacific Island states, particularly vulnerable to SLR and facing the reduction or complete loss of maritime entitlement, have been driving legal developments in this area, and have adopted a uniform and collective approach of legally preserving baselines, maritime zone entitlements, and boundaries despite the occurrence of SLR.
Two international bodies of legal scholars and experts, the International Law Association (ILA) and International Law Commission (ILC), are also examining these issues in the broader context of SLR and international law, motivated in part by the risk that SLR poses to the certainty of unilateral limits and boundaries and consequent implications for international stability and security.
To this end, this article will explore the potential implications of SLR for the maritime security of Southeast Asian states through the lens of SLR’s impact on maritime jurisdictional clarity. The analysis is divided into three parts. Section 2 outlines current practices of Southeast Asian states on baselines, maritime zone outer limits, and maritime boundaries. Section 3 examines Southeast Asian states’ approaches to SLR in the light of current discussions on its legal effect on baselines, maritime zones and maritime boundaries. Section 4 makes some preliminary observations on the implications of SLR for jurisdictional clarity (and consequently maritime security) in Southeast Asia. Section 5 concludes by making some suggestions on how Southeast Asian states can mitigate the impacts of SLR from a legal perspective and highlights certain challenges that they may face in doing so.
This article focuses on SLR’s impact on baselines, maritime zones and maritime boundaries generated from the mainland coast of Southeast Asian states and excludes analysis of maritime claims made from the features in the South China Sea, which raises different issues.20 It also does not discuss the legal implications of the complete loss of territory (and consequent loss of maritime entitlement) resulting from SLR, but confines the analysis to its impact on unilateral limits and maritime boundaries, which may result in a reduction of maritime entitlement.