From the end of the 19th century to the beginning of the 20th century, Japan pursued a policy of imperialistic expansion. Japan won the Sino-Japanese war in 1894 and the Russo-Japanese war in 1904; the main issue at stake in both wars was control over Korea. After having beaten off its two colonial rivals, Japan forced Korea to become its protectorate in 1905, and finally annexed Korea by force in 1910. In the course of this imperial aggression, the Shimane Prefecture, a Japanese local authority, adopted a municipal ordinance to incorporate Dokdo into its jurisdiction without legal foundation and without notifying any state concerned. In this way, the invalid acquisition of Dokdo by Japan was conducted in the process of and as a part of Japan's annexation of Korea.

After the Second World War, Korea, being liberated from Japan, recovered its territory, including Dokdo. During and after the Second World War, the Allied Powers adopted a series of documents which contained provisions intended to make Japan return the entire pre-colonial Korean territory, including Dokdo, to Korea. These provisions are as follows:

The 1943 Cairo Declaration states: "Japan will also be expelled from all other territories which she has taken by violence and greed".

The 1945 Potsdam Declaration declares: "Japanese sovereignty shall be limited to the Islands of Honshu, Hokkaido, Kyushu, Shikoku, and such minor islands we determine."

When it surrendered to the Allied Powers in 1945, Japan unconditionally accepted the Potsdam Declaration. The Allied Powers have never subsequently determined that Dokdo is part of the territory of Japan.

The 1946 SCAPIN (Supreme Commander for the Allied Powers Instruction) No. 677 specifically excludes Dokdo (referred to as Liancourt Rocks) from Japan's territory as follows: "For the purpose of this directive, Japan is defined to include: the four main islands of Japan... excluding Utsuryo Island, the Liancourt Rocks and Quelpart Island."

The 1951 San Francisco Treaty of Peace with Japan stipulates in Article 2(a): "Japan recognizing the independence of Korea, renounces all right, title and claim to Korea, including the islands of Quelpart, Port Hamilton and Dagelet."

Although there are about 3,000 Korean islands, these three major islands are the only ones mentioned in the San Francisco Treaty. The fact that Ulleungdo (referred to as Dagelet) is one of the islands mentioned would indicate that its smaller neighboring islands, including Dokdo, were implicitly included into the above provision of the treaty.