Syngman Rhee Line

The Syngman Rhee Line (Hangul: 이승만 라인) refers to a boundary line established by South Korean President Syngman Rhee in his "Peace Line" (평화선) declaration of January 18, 1952, which included the Liancourt Rocks in Korean territory.

Rhee stated that the purpose of the line was to protect Korea's marine resources around the Sea of Japan; therefore it banned non-Korean fishing boats from inside the territory, and Liancourt Rocks in particular.

South Korea had demanded that the MacArthur line established after World War II continue to be enforced, though on August 10, 1951, the United States sent Korean Ambassador Yang You Chan the Rusk documents, stating that the official policy of the United States was that the MacArthur line would be abolished by the Treaty of San Francisco. The treaty was signed on September 8 of the same year, about a month after the documents were sent, and was to come into effect on April 28, 1952. In response, the South Korean government declared the Syngman Rhee Line three months before this date, when the extinction of the MacArthur line and the return of sovereignty to Japan were meant to be established.

According to the Report of Van Fleet Mission to Far East made in 1954, the U.S. government maintained that the one-sided declaration of the Syngman Rhee Line was illegal under international law.

A Japanese demonstration against the line (September 15, 1953)

The fishing boats - which were mostly Japanese - that violated the boundary line were seized by South Korea. Japanese records claim that such ships were often fired upon. The Japanese government protested the seizures and unilateral declaration strongly, but the abolition of the line had to wait even for the approval of the Japan-Korea Fishery Agreement in 1965. By the time an agreement was reached, 3929 Japanese people were arrested, of whom 44 were killed, and 328 Japanese ships were seized.

At the behest of the South Korean government, in exchange for the release of Japanese fisherman detained as a result of the line, the Japanese government released 472 Koreans in Japan who had been imprisoned as criminals. Those released gained the permission of residence (they became Zainichi).