It is said that the inherent territory theory was invented by Japan. Japan, which lost a lot of territory after its defeat in World War II, began to raise claims of ‘inherent territory’ in order to recover such territory. The first time the claim of ‘inherent territory (固有の領土)’ was used for the two islands, Habomai and Shikotan, on the border with Russia. Afterwards, in 1956, Japanese Foreign Minister Mamoru Shigemitsu stated in a speech to the National Assembly that Dokdo was also Japan's inherent territory. In general, ‘inherent territory’ means ‘national territory that has never historically become the territory of another country’ or ‘unique national territory that has not been newly acquired through the mode of territorial acquisition.’ It is distinguished from ‘territory possessed since the establishment of a modern state’ or ‘territory possessed ab origine at the time of the establishment of a modern state, and territory acquired by gains after the establishment of the state.’ Inherent territory is understood to include three aspects: 1) the temporal and historical part, 2) the mode of territorial acquisition, and 3) the absence of foreign domination. Although the inherent territory theory seems similar to historical title at first glance, it is reasonable to believe that the inherent territory theory claimed by Japan is virtually impossible to apply not only under international law but also in actual reality, and is unlikely to be accepted as a theory under international law.
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