Northeast Asian History Network

There is a theory in international law regarding whether national sovereignty can be claimed on the grounds of geographical proximity. This is the discussion of geographical contiguity. Geographical contiguity may also be called geographical proximity, continuity, or territorial propinquity.^{[note 079]}For example, an island located close to the mainland is more likely to belong to the mainland. For an archipelago, the sovereignty of the main island tends to determine that of all other islands within the archipelago.^{[note 080]}Geographical contiguity can be divided into two different cases. One is related to islands, in the case in which an island is close to the mainland or the relationship between the main island and other smaller islands in an archipelago. The other case concerns contiguous land in which one region is related to another.^{[note 081]}The theory of geographical contiguity began to emerge in the late nineteenth century when European powers scrambled for territory in Africa. The theory was called the hinterland doctrine. This doctrine states that a power may argue for territorial rights in the hinterland based upon occupation of a sliver of land on the coast.^{[note 082]} But this theory was overturned by the 1885 General Act of the Berlin Congress, which stated that for any power to establish territorial sovereignty in African coastal lands, local governments must be established.^{[note 083]}Later, another territorial sovereignty theory called the sector theory emerged in disputes surrounding the polar regions in the Arctic and the Antarctic.^{[note 084]}The sector theory was raised by countries close to the polar regions, such as Canada, Russia, Denmark, Chile, and Argentina, in response to claims by non-contiguous countries that argued for their sovereignty based on first discovery. This is a claim that the islands and continental lands within a fan- shaped area surrounded by two longitude lines and a latitude line with the north or south pole as the summit point belong to the nation closest to them.^{[note 085]} But, in the end, this argument was not accepted as the majority opinion due to opposition by non-contiguous countries and the signing of the Antarctic Treaty that forbade national sovereignty on any part of the continent.


In relation to the theory of geographical contiguity, the best case can be found in an international legal dispute surrounding the Island of Palmas (Miangas) in 1928. In this legal case, the United States side argued for territorial ownership based on the theory of geographical contiguity and the principle of discovery. According to the claims by the attorneys for the United States, the United States succeeded to the sovereignty of the island from Spain when it signed the Treaty of Peace on December 10, 1898, with Spain to take over the Philippines from Spain. The Island of Palmas is located 77 kilometers off Mindanao, the Philippines, to the southwest and 82 kilometers off Nanusa, Indonesia. The Philippines side is about five kilometers closer.^{[note 086]}Max Huber, the arbiter for this case, stated that there is no legal ground anywhere in international law that can grant geographical contiguity as the primary source of sovereignty to land.^{[note 087]}He elaborated on this point as follows.^{[note 088]} As to the reason for this, Huber wrote, “Not only would it seem that there are no precedents sufficiently frequent and sufficiently precise in their bearing to establish such a rule of international law, but the alleged principle itself is by its very nature so uncertain and contested that even governments of the same state have on different occasions maintained contradictory opinions as to its soundness.”^{[note 089]} In other words, the theory of geographical contiguity is flawed in its precision and may lead to arbitrary outcomes in its application as well.
Still, one cannot say with confidence that an argument based on geographical contiguity is useless when it comes to land acquisition. Let us consider the example of the Island of Palmas. The island, which is 3.15 square kilometers in size, was inhabited by 750 residents at the time of the 1928 lawsuit.^{[note 090]} At the time, Palmas enjoyed a certain degree of independence as can be seen in the signing of an agreement establishing suzerainty with the Dutch East India Company and the government of Holland by tribal chiefs in surrounding islands, including the Island of Sangi.
If the island was uninhabited or located much closer to the Philippines, the conclusion would have been different. The main reason Huber ruled against the American argument based on geographical contiguity was probably not because this theory was not sufficient to constitute firm sovereignty claims but because the Dutch argument was superior. The Dutch government, through the hands of the Dutch East India Company, signed suzerainty agreements with tribal chiefs, dispatched government officials for visits, created military uniforms and military flags that could function as external symbols of sovereignty, and assessed local taxes. All in all, the Dutch side was relatively superior in effective rule.^{[note 091]} In addition, the Spanish government had not expressed its sovereignty, directly or indirectly, over the island for a long period of time since its discovery in the sixteenth century. The government did not even protest the exercise of territorial sovereignty by the Dutch.
Of course, the most important element to win in territorial disputes is continuous and peaceful exercise of state power over the contested land. Once this condition of effective exercise of state power can be satisfied, the sovereignty argument based on geographic contiguity will gain more power in a lawsuit over territorial claims.^{[note 092]} In other words, geographic contiguity by itself is not sufficient for arguing territorial claims, but nonetheless can be an important factor in evaluating a state’s effective rule over the contested land.
In sum, the argument based upon geographic contiguity cannot be as strong an argument as continuous and peaceful exercise of state power through effective rule. For uninhabited islands with no self-sufficiency, however, the argument may be proposed as prima facie evidence that can help estimate the effective rule.^{[note 093]}

Dokdo consists of two large islands – East Islet (73,297 square meters) and West Islet (88,740 square meters), as well as 89 rocks in surrounding waters. The total size of 187,554 square meters is about 1.7 times larger than Independence Park in Seoul, which is 109,194 square meters. The closest island from Dokdo is Ulleungdo. The distance between Dokdo and Ulleungdo is 87.4 kilometers (47.2 nautical miles). The next closest island from Dokdo is the Oki Islands, Japan, whose distance from Dokdo is 157.5 kilometers (85.0 nautical miles), or 1.8 times farther than that from Ulleungdo.
As seen above, it is difficult to argue territorial sovereignty over Dokdo based solely on geographic contiguity. Some even raise an objection, saying, “Can we argue territorial ownership over Tsushima just because it is visible from Busan?” But one needs to distinguish cases between long-inhabited islands such as Palmas and Tsushima and uninhabited islands such as Dokdo. For inhabited islands, the simple fact that they are visible from one side of the mainland means little for territorial sovereignty.
In contrast, in the case of Dokdo there had been no permanent residents until the installation of the frontier guards in the early 1950s. The settlers there were only temporary or seasonal. As will be clear from Section IV on “Historical and Geographical Integrity” below, one must distinguish cases from long-inhabited islands. In this case, geographic contiguity can be used to estimate historical title or effective rule on Dokdo.