Maritime boundaries mark the limits between territorial waters and the open sea where navigation is subject only to the rules of international law. The extent of territorial waters, in the past, was limited to three nautical miles because this was the maximum range of coastal guns: it was, therefore, the truly defensible strip of sea. Today the question of extent is no longer so much related to defensive issues (since modern missiles can cross the seas from end to end), but rather to economic interests. Coastal states indeed tend to expand their territorial waters in order to secure exclusive exploitation of fisheries resources or submarine deposits. The Convention on the Law of the Sea, signed in 1982 in Montego Bay, Jamaica, sought to bring some order to the issue of territorial waters by setting their maximum extent at 12 nautical miles from the coast. At the same time the existence of a so-called “exclusive economic zone” extending up to the 200 nautical mile limit from the coast was recognized. The economic resources obtainable within this arm of the sea belong to the coastal state, but the right of navigation, overflight and any other rights recognized by international custom remain unaffected for other states. Not all states have adhered to this convention, and this still leaves room for frequent and sometimes bitter disagreements. The Underwater Dimension hosting gas pipelines, power lines, internet and communication cables, and extremely rich in minerals in the seabed, etc., needs to be contextualized in the current and future geopolitical confrontation between the U.S. and China.
For China, expanding its maritime borders beyond Taiwan means projecting its nuclear deterrence (especially via submarines) closer to the U.S.. For Russia, considering its borders 200 kilometers closer to Finland expands its sphere of power and moves NATO action away from its territory. With the U.S.-dominated Post-Cold War period over, a new era of confrontation and, unfortunately, not of geopolitical cooperation has begun, especially in the Indo-Pacific area, which has become the quadrant of confrontation between the U.S., with its allies, and China. In this context, the undersea domain has become increasingly relevant with the emergence of the concept of Underwater Domain Awareness of the securitarian risks associated with increasing human dependence and activity in the deep sea and the possibility that it may be subject to malicious surveillance or attack.
Indeed, operating below the surface, in the absence of adequate control of the underwater environment, can lead to actions contrary to national security and interests, thus affecting the conduct of economic, commercial, civilian and military activities. Corridors related to energy supply, mineral resources, connectivity, gas and oil pipelines, as well as data traffic transmission backbones make the underwater environment strategic in many respects and as such vulnerable to the influence of competitors, through submarines and other means including unmanned, such as underwater drones, which represent a leading high-tech and naval and defense industrial output. An increasingly contested and chaotic sea, where numerous regional actors aspire to control and exploit growing portions of the deep sea, and where disagreements among many states over their respective Exclusive Economic Zones (EEZs) bring to the forefront the issue of Submarine Boundaries and the growing activity to police activities below and above the sea and for potential conflicts.
