In the first part of this article series, I outlined the situation of small island nations threatened by climate change and highlighted how Tuvalu – the “spokesperson” of the four most endangered countries – is taking steps to confront this existential challenge. In the subsequent sections, I will explore further strategies available to these nations to preserve their statehood.

1. The Death of the State?

What happens if states do not recognize statehood on a continuing basis, or if an insufficient number of states grant such recognition? In that case, the ‘death of the state’ occurs, the end of statehood. Scholars who argue that the defining conceptual conditions necessary for the creation of statehood can withstand a certain degree of fluctuation (such as territorial variation, drastic population decline, or governmental instability) maintain that the complete absence of any one Montevideo criterion, however, is not permissible.

The UN Charter does not contain any provisions regarding the extinction of states or the automatic loss of their UN membership. It does, however, provide for the expulsion of states, because a member state that has “persistently violated the Principles” of the Charter “may be expelled by the General Assembly upon the recommendation of the Security Council”. Nonetheless, even with the UN’s inaction on this matter, it remains possible that some states may choose not to recognize the island as a state. It cannot be clearly determined how many states would need to vote in such a manner for statehood to be considered, from the perspective of international law, as having ceased to exist. However, this solution is clearly unjust, as it effectively ‘punishes’ the small states that have contributed the least to climate change. Let us examine what other legal approaches could be used to address the problem!

2. Possible Solutions

The disappearance or reconfiguration of states, when viewed in historical perspective, can be considered a common phenomenon, as several states have ceased to exist due to political or military events. However, the dissolution of a state has never yet been caused by a physical occurrence, and therefore no precedent exists for the situation under discussion. Let us therefore examine, in light of our question, what parallels may be drawn from earlier situations under international law and what entirely new conceptual solutions might be outlined.

2.1. The Silent Continuation of Statehood

A potential solution lies in the implicit or explicit preservation of statehood and the continued recognition of sovereignty. In this scenario, statehood is artificially maintained by other states, as they act as though nothing has changed. This concept requires no formal amendments to international law; it merely involves the maintenance of the status quo, effectively ignoring the fact that the submerged state’s territory has ceased to exist (or has become entirely uninhabitable as it lies underwater). Article 6 of the Montevideo Convention also states that “Recognition is unconditional and irrevocable.” This sentence clearly supports the position of those who argue in favor of the continuity of statehood, as the Convention essentially concerns the creation of states and does not contain any mechanism for determining either the continuity or the extinction of existing ones. The problem, however, as previously noted, is that members of the international community may begin to interpret the situation differently. For this reason, the ideal solution would be for the UN General Assembly to adopt a resolution affirming the principle of the perpetual existence of states, regardless of sea-level rise or other natural disasters. This would remove the need for any individual state to explicitly declare that it recognizes submerged island nations even without territory. A statement from the UN Security Council would likewise be extremely valuable.

2.2. The Movement of the Population

In this case, the entire population, all together as a group, would move to another state, to a territory designated for them. This would not involve gradual emigration or dispersal (although that is already the case in Tuvalu’s situation, as many have settled in Australia or New Zealand). There are numerous historical examples of mass relocations in which the movement of large groups of people was regulated through agreements governing citizenship and the rights of those relocated. In most cases, however, such mass relocations were forced, resulting from war or religious tensions (for example, the expulsion of the Sudeten Germans after World War II, the deportation of the Crimean Tatars, or the partition of India in 1947). There has never yet been a precedent for permanently relocating an entire state’s population due to a natural disaster.

2.3. Unification with Another State

Some states in the past have become unified with others, either by being absorbed into them or by forming a new sovereign state. An example of this is the union of Tanganyika and Zanzibar in 1964, which created Tanzania, but other (re)unified states can also be mentioned, such as Vietnam (from 1976 to the present) or Czechoslovakia (from 1918 to 1993). The examples of these states are, of course, quite distant from the fate of submerging nations; however, they could still serve as a formal solution, as they demonstrate that a state’s status can be settled without declaring its dissolution. The inhabitants of a sinking island, in principle, could thus “relocate inland“.

2.4. Acquisition of Territory

In theory, there is also the possibility – although I am almost certain it could never be realized in practice – that a climate-affected state might acquire a higher-lying, still unsubmerged island or mainland territory from another state. The host state would transfer territorial ownership and cede sovereignty over that area as well. This could be accomplished by a treaty of cession, since de facto there is no longer any terra nullius left on Earth (neither Liberland nor Bir Tawil is practically “inhabitable“). Therefore, the new establishment of such a state could occur only at the expense of, or with the support of, another state.

There are also historical examples of territorial transfer, particularly in the case of the United States, which, in international terms, purchased the largest territories. In 1803 it acquired Louisiana from France, in 1854 it purchased the southern parts of what are now Arizona and New Mexico from Mexico, and in 1867 it bought Alaska from Russia. In the twentieth century, peaceful acquisitions of territory became far rarer. One of the most significant was the purchase of the Gwadar region in 1958, when Pakistan obtained 15,000 square kilometers of land from Oman along the coast of Balochistan. More recently, in 1963, Germany repurchased the territories of Elten, Selfkant, and Suderwick from the Netherlands (these three towns had been occupied by the Netherlands in 1949 as part of war reparations). In 1998, as part of the settlement of the Ecuador–Peru border dispute, Peru transferred one square kilometer of land to Ecuador in the form of “private property“ for the construction of a memorial and the maintenance of the graves of Ecuadorian soldiers. The transfer occurred without compensation and was legally considered private land. As we can see, these examples differ from the case under examination, as they are rooted in various historical contexts, and the acquiring states’ intentions were not to (re)establish entire new states but rather to expand existing territories.

One of the many issues arising in connection with the scenarios of population relocation and territorial transfer concerns what happens to the inhabitants, since there are hardly any long-term habitable areas left on Earth that are not already populated. A deterrent example of population resettlement into territories already inhabited by other peoples is the case of Israel, where, even after nearly eighty years, conflicts in the region remain ongoing.

2.5. Restitution

In theirdeclarations , Judges Aurescu and Bhandari suggest that the restitution provided by the community of states responsible for the climate catastrophe could include the recognition of the continued statehood of the submerged nations, as well as of their rights related to their existing maritime zones. In this context, the issue may arise of acquiring territory granted as part of restitution – specifically, whether a state could be compelled to cede even a small portion of its land (given that the territories of the island states in question are negligible in size compared to others). Since sea-level rise constitutes the “collective sin” of the international community, it would not be lawful to single out one state as primarily responsible and compel it to transfer territory. Moreover, it seems quite unlikely that any state would voluntarily comply with such a request. As discussed earlier, this could only conceivably occur in exchange for compensation – that is, through the submerged state purchasing land using its remaining resources.

2.6. Deterritorialized State

The concept of a deterritorialized state requires far more radical changes. It cannot be achieved on the basis of any existing precedent and would clearly call for legal reform. The government of such a deterritorialized state would be elected by its population but would conduct its affairs from the territory of another state. It would remain responsible for the state’s remaining assets (for example, its maritime zone, although the status of such assets after the complete submergence of land presents a complex question). The population would obviously live in diasporas, as already seen in the case of Tuvalu, whose citizens have relocated to Australia in great numbers. The government would continue to exercise its sovereign powers and represent the rights of its citizens, from a distance.

The essence of this concept is that, unlike the approach of continued recognition, it would ensure the preservation of statehood on a permanent and objective basis – under international law – rather than on a contingent one dependent on the discretion of individual states. Its implementation would, however, require the introduction of a new category of states into international law and the definition of the privileges that a deterritorialized state would continue to possess, as well as those that it would lose due to its physical impracticability. For example, such a state could still retain the right to issue passports, grant citizenship, participate (through membership) in the work of international organizations, maintain diplomatic relations, appear before international courts, and conclude international agreements (treaties).

At least two precedents demonstrate that the concept of deterritorialized statehood is not foreign to international law: the Sovereign Military Order of Malta and the Holy See (between 1870 and 1929). But are these, in fact, true states – or rather distinct constructions under international law?

The Sovereign Military Hospitaller Order of St John of Jerusalem, of Rhodes, and of Malta (hereinafter “the Order“) is currently the only organization in the world that, albeit controversially, is recognized by a significant majority of states as sovereign or quasi‑sovereign, despite not possessing any territory. In its own Constitutional Charter and Code, the Order defines itself as “a subject of international law” and “exercises sovereign functions.”

Founded in Jerusalem, the Order settled on Rhodes between the 14th and 16th centuries. After an Ottoman siege, it was forced to flee and relocated its headquarters to Malta, where it operated from the 16th to the 18th century. In 1798, following Napoleon’s conquest of Malta, the Order was expelled. Since 1834, it has been headquartered in Rome, where its three‑hectare Palazzo Malta enjoys extraterritorial status, though not sovereign territory. Today, the Order maintains diplomatic relations with multiple states and exercises sovereign functions such as issuing official documents, license plates, and postage stamps – despite lacking both territory and population in the classical sense. In 1994, the United Nations General Assembly granted the Order permanent observer status, recognizing its humanitarian mission and unique role in international humanitarian affairs. Representatives of the Order participate in the work of various international organizations, including UNESCO, the FAO, WHO, and the UNHCR. Its international legal personality and diplomatic presence – particularly given its humanitarian activities – thus persist, even in the absence of territory.

This year marks the centenary of diplomatic relations between the Sovereign Order of Malta and Hungary. The Order has been active in Hungary since the 12th century, but formal diplomatic relations were only established in 1990, following the transition to democracy. In 2024, the Grand Master of the Order received from the President of Hungary the Grand Cross with Chain of the Hungarian Order of Merit – an award previously reserved only for heads of state and sovereigns. This example clearly illustrates that, in certain contexts, the Order is indeed recognized as a state.

The period from 1870 to 1929 presents another interesting international law anomaly, the existence and continued international activity of the Holy See despite its loss of territorial sovereignty. This era, known as the Roman Question, began when Italian forces captured Rome in 1870, effectively ending the centuries-old Papal States. Pope Pius IX lost control over the extensive Papal States with a population of over three million across central Italy. Following a plebiscite, which overwhelmingly favored annexation, Rome and the remaining papal territories were formally incorporated into the Kingdom of Italy through a royal decree. Despite losing territorial sovereignty, the Holy See maintained its international legal personality and continued active diplomatic relations throughout this period. Far from declining, diplomatic engagement with the Holy See actually expanded during this period. In 1870, sixteen states maintained permanent representations to the Holy See. By 1929, twenty-seven states had diplomatic relations with the Holy See – all established before the creation of Vatican City State. Between 1870 and 1929, the Holy See signed numerous concordats and agreements with various states.

As a basis for comparison, the Order of Malta and the Holy See naturally come to mind. According to the literature, they are best described as “sui generis non‑State sovereign entities” – that is, not states per se, yet they participate in international relations on an equal footing with land‑possessing states. In reality, therefore, they do not serve as precedents for disappearing island nations, since they were not deterritorialized states, but rather legally proximate, non‑state sovereign entities situated in a kind of gray zone between statehood and non‑state personality.

Gellért Magony JD is a PhD student in law at the Doctoral School of Law and Political Sciences of the Pázmány Péter Catholic University in Budapest (Hungary). He is a graduate of the University of Szeged (Hungary) with a degree in law, where he worked for many years with the Institute of Public Law in different research projects as a student fellow. His main research interests are constitutional law and media law.