Does the ‘defined territory’ include submerged land?

Some notes on the notion of ‘territory’ regarding legal concerns presented by sea level rise

Currently, territory is considered synonymous with the State. This is due, in part, to the geographical conditions which were understood, until now, to be relatively stable and definite and, therefore, integral to a system that shares these same characteristics. With climatic changes and their principal manifestation – the rise in sea levels – this traditional notion, which for many is obsolete, is at risk because it undermines the territorial foundation of the State. This is due to the loss of one of the material components of the State – territory – a loss arising from natural conditions and not from political changes as has been the case until now on the international scene. Climate change has normative effects on International Law, especially on the Law of the Sea and Law of Statehood, as we are experiencing a new epoch in geological history, the Anthropocene (See Davor Vidas et al.). The sea level rise is one of the main consequences of climate change, which is leading to flooding in coastal areas. This affects low-lying coastal regions which are especially vulnerable to climate events, as well as territoriality as a defining attribute of the Westphalian State. In effect, many Pacific States are at risk of being submerged and, according to classic International Law, a State cannot continue to exist without territory.

But… What kind of geographical space can be understood as ‘territory’? This article examines the legal implications of the sea level rise on the territory of the State. It aims to examine the question of whether the “submerged territory”, after the physical disappearance of the State’s territory (loss of the element ‘territory’), can be regarded as ‘territory’ for the purpose of maintaining the legal personality of the State.  In this regard, I argue that the territory has to support habitation or economic life of its own, according to the interpretation of international legal instruments.

Loss of the material element “territory”

The conception of State has shown to be impermeable despite its organic character. The traditional State system on which international law currently lies falls into the “territory narrative”. However, “territory” is not an unchanging reality, on the contrary, it is a mark of a certain stage of political and social evolution (see Scelle). The territorial feature of the system of international law corresponds to the need for a physical space for the State to realize its power. As a requirement (Article 1 Montevideo Convention), the territory serves as i) physical support of the population requirement, ii) it does not require a minimum dimension as to population density, iii) there is no need for precise territorial delimitations, that is, it supports unsettled/disputed borders (see James Crawford). Currently, the territory can be seen as consubstantial to the State. This is partly due to the relatively stable geographical conditions we have been experiencing until now and, therefore, fruitful to a system sharing these same features. The State’s traditional conception, for many Scholars already outdated, is changing due to environmental considerations, and, mostly, due to a new cause of extinction: territory submersion or submersion of a State (IPCC). Climate change phenomenon (especially one of its consequences, that is, sea level rise), calls into question two important foundations under international law: on the one hand, i) the territorial foundation of the State, and, on the other hand, ii) the structure of maritime zones and, therefore, the construction of its sovereign maritime rights, that is, the core of Law of the Sea mainly based on the geography of coastal states. In addition, the rise of sea levels contradicts the very principle of universality because it calls into question the principle of stability of borders and the principle of succession of States. This is due to the loss of one of the components of the State – the territory -, a loss stemming from natural conditions (environmental degradation leading to the submersion of islands and other territories) and not from political changes as they have occurred over time on the international scene.

Territory includes not only land but also marine space, including internal waters and territorial sea (Article 2 (1) UNCLOS – United Nations Convention on the Law of the Sea). International Law dictionaries define territory as a ‘geographical area included within a particular government’s jurisdiction; the portion of the earth’s surface that is in a State’s exclusive possession and control” (Black’s Law Dictionary, 2004, p. 1512), thus including marine areas that are under the sovereignty of the State.

In International Law, a State must have a ‘defined territory’, without a requirement for a territorial dimension. This is being debated in the Convention: whether an island made uninhabitable by submersion or a low-tide elevation can fulfil the requirements of ‘defined territory’ (here, ‘rock’ in Article 121 (2) of the UNCLOS). In fact, it is questionable whether a submerged territory can meet the criteria of ‘territory’, when this physical territory does not ‘disappear’, but rather remains submerged, inaccessible, and, consequently, incapable of sustaining human habitation. We can distinguish three circumstances: i) the case in which the territory is partially submerged, but the remaining territory is habitable; ii) the case in which the territory is uninhabitable, but not totally submerged (partially submerged); and iii) the case in which the territory is completely covered by sea (total submersion).

In the first case (territory that is partially submerged, but is habitable), while the State maintains some physical territory, regardless of its extent, there will be no problem with regard to its legal status. In the second case (partially submerged territory, but uninhabitable), knowing whether a territory is uninhabitable is the issue, but even with the emerging territory, it still qualifies as a State according to Article 1 of the Montevideo Convention. In the third case (total submersion), knowing whether a territory that is completely submerged fulfils the requirement of ‘territory’ is the issue. It is with regard to these last two cases that this issue gains greater relevance.

Once there is no minimum limit to the spatial dimension of the territory, a territory that is temporarily or permanently covered by water could be considered in an abstract sense to meet the requirement of the term ‘territory’. In spite of the fact that a rock can be considered a ‘territory’ for the purposes of the UNCLOS (see Susannah Willcox, p. 8), the majority of the Scholars considers that it is not sufficient to meet the requirement for ‘defined territory’ as enshrined in the Montevideo Convention, since the requirement for ‘territory’ is based on the premise that it is capable of sustaining human habitation or economic life of its own. A territory without people is meaningless; therefore, it cannot be a State. These two conditions (human habitation and economic life of its own) are linked to the requirement for effective control of a defined territory, for which the State must show this effective control. It has been suggested that certain portions of sea territory can also be occupied, as the Albanian Declaration made clear in the Corfu Channel (here p. 142 § 145) case when it referred to the occupation of its internal waters by British ships.

However, it appears that according to the UNCLOS, there is no legal difference between inexistent territory and inaccessible territory (inaccessible because it is submerged). From Articles 40 (5), and 57 of the UNCLOS, it is patent that a submerged territory does not lead to any right to a marine space or any of its resources. Article 121 (1) reflects this position by making territorial claims conditional on the ability to control and use it. So, when human life and economic activity cannot be conducted underwater, the submerged territory can hardly be considered ‘territory’, according to the definition in the Montevideo Convention. In this context, Alberto Costi and Nathan Jon Ross also state that: “[…] islands, including coral atolls, are part of a State’s land territory. However, according to the UNCLOS definition, if an atoll is inundated and disappears, or is flooded at high tide, it will no longer constitute an ‘island’. As such, it is unlikely to be considered land territory, as required by the UNCLOS. If this is to occur to all islands of a low-lying State, there will no longer be any land territory” [see Costi and Ross, p. 111].

Therefore, the fulfilment of the requirement of the territory through ‘submerged territory’ cannot be considered possible, as there is an unavoidable link between the requirement for ‘permanent population’ and ‘territory’, and the criteria of the territory reflect the relationship between its people and the geographical space in which they live. Consequently, the solutions identified by the Convention will be important for the construction of coastal protection to guarantee the habitability of the territory.

As a consequence of the use of low-water line as the baseline from which coastal areas are measured, “islands presently above the water surface at high tide may, as a result of sea-level rise, disappear at high tide and become low-tide elevations, resulting in the feature being reclassified from an Island to an insular feature.” With respect to low-tide elevations (Article 13 UNCLOS), Authors and Jurisprudence are unanimous that a low-tide elevation does not meet the requirement for ‘territory’ [see ICJ, Maritime Delimitation and Territorial Questions Between Qatar and Bahrain, 16 march 2001 § 206].

In the matter of the dispute between the States of Nicaragua and Colombia, the ICJ [the International Court of Justice] ruled that in contrast to Islands – which can be the object of territorial appropriation – “low-tide elevations cannot be appropriated” [see here, p. 641 § 26]. The conclusions drawn from these cases appear to be valid, even if the low-tide elevations include lighthouses or similar installations above high-tide, since there is a substantial distinction between Islands (above water at high tide, Article 121 (1) of the UNCLOS) and formations submerged at high tide (Article 13 (1) of the UNCLOS).

The definitions in the UNCLOS suggest, therefore, that the territory on which the State exercises jurisdiction depends on the existence of a portion of land above water at high tide.

What if the territory is understood as an object of the State?

However, if we consider territory as a fungible asset, or as an object of the State, territory external to the State could be considered a fungible asset with regard to questioning the premise of the perpetuity of its geophysical territory, which would make it possible to consider the transfer of a whole State to the territory of another. This position opens the door to a relativisation of the relationship between the State and its territory. Such a characterisation could raise the possibility of distinguishing the State from its territory, or even circumventing the need of any State to have an emerging territory. It is in accordance with this second notion that mechanisms aimed at avoiding the ‘natural death’ of the State were envisaged. This theory thus considers territory as being the property of the State – territory is understood as something the State possesses, and not what the State is; territory is an object over which the State exercises dominion. This theory considers territory as something extrinsic to the State and does not take into consideration the need of a State to possess territory in order to exist. Questioning the premise of the perpetuity of the geophysical territory of States leads to considering the territory (area of spatial validity of the State’s parameters) as a fungible asset from the point of view of International Law: if the territory is conceived as a place in which the parameters are applied to people, such parameters can be simply modified and people moved to avoid the effects of submersion of the whole territory, which, according to this theory, would be possible without the State legally ceasing to exist.


Accordingly, the requirement for ‘defined territory’ [Article 1(b) Montevideo Convention] appears not to include submerged territory because, in order to satisfy this requirement, the territory has to support habitation or economic life of its own (as explored in light of the UNCLOS), elements linked to the requirement for effective control over a defined territory (interdependence of the constituent elements). Under the Principle of Effectiveness [See Grisbadarna case: “it is a settled principle of the law of nations that a state of things which actually exists and has existed for a long time should be changed as little as possible”, p. 6], States without physical territory could not be effective due to their inability to exercise control over the (lost) territory and (displaced) population. The territory (a physical area where sovereign powers are exercised over a permanent population) must act as a functional feature of the State. It flows from the interpretation of the territory as a piece of land. As populations cannot survive without land territory, that is, cannot survive in a submerged territory, compliance with the effectiveness criterion requires the territory to be habitable in order to remain functional and effective. Instead, according to some readings of the territorial element, the loss of the status of the State would not be simultaneous with the loss of the territory, accordingly, the State would not cease to exist: one could interpret the territory as an object of the State (it would be legal any transference of an entire State to the territory of another, e.g., cession of the territory by treaty through which a State acquire sovereignty over a portion of land).

The future of “disappearing States” after the loss of their territory is still open to debate. There are no closed legal paths nor final answers. Despite its legal novelty and yet uncertainties on the physical disappearance, the international community, together with scientific developments, legal Literature, and State practice [see here], must combine efforts for a joined response integrating the need for stability and flexibility of international law regarding the adaptation to the natural extinction of States. The ILC should have a decisive role in this regard [see, for instance, the first issues paper of the Study Group on sea-level rise in relation to International Law].


Daniela Martins is a Ph.D. in Law candidate at the University of Lisbon School of Law. Her research focuses on the geographical changes that affect coastal and maritime features and their implications under the law of the sea. She aims to explore the legal effects of sea level rise on maritime delimitations. She is involved in research projects in the field of international law, which special regard to the law of the sea and climate change law.