Japan had been at war with Russia over its interests in Manchuria and the Korean peninsula since 1904. Japan’s attempt at incorporating Dokdo into its own territory through the Shimane Prefecture Public Notice No. 40 in 1905 was aimed at meeting its military needs in the face of possible maritime clashes with Russia in the East Sea.

In a related Japanese historical document it is recorded that the territorial incorporation of Dokdo was being pursued based on the opinion of a Ministry of Foreign Affairs’ official that “building a watchtower and installing radio transmissions or submarine telegraph communication systems on Takeshima [Dokdo] would give us an advantage in terms of monitoring enemy ships.” Yozaburo Nakai, who petitioned for the territorial incorporation of Dokdo, had initially perceived Dokdo as Korean territory.
Also, an official of Japan’s Ministry of Home Affairs stated, “… the disadvantages of arousing the suspicion that Japan harbors the ambition to annex Korea outweigh the advantages … by seizing the barren rocks [Dokdo] where not a blade of grass grows and which are considered as belonging to Korea…” This points to the Japanese government’s recognition of Dokdo as Korean territory.

In February 1904, Japan compelled the Korean Empire to sign the Korea-Japan Protocol to ensure unlimited access to Korean territory in the execution of the Russo-Japanese War. Japan also coerced the Korean government to appoint Japanese and other non-Korean nationals as advisors through the First Korea-Japan Agreement in August 1904. In effect, Japan was systematically implementing its plan to take over Korea, and Dokdo was the first Korean territory to fall victim to Japanese aggression against Korea.

As is thus shown, the Shimane Prefecture Public Notice No. 40 was part of Japan’s systematic plan to undermine Korea’s territorial integrity. Japan’s attempt to incorporate Dokdo into its own territory was an illegal act that infringed upon Korea’s undeniable sovereignty over the island, which had been established over a long period of time. Accordingly, the Shimane Prefecture Public Notice No. 40 is null and void under international law.