Foreign relations of South Korea
On January 18, 1952 The first president of South Korea Syngman Rhee declared that the vicinity of Dokdo was a territory of South Korea (Syngman Rhee line). Subsequently, some 3,000 Japanese fishermen who conducted fishery operations in this vicinity were captured. This incident, called the Dai Ichi Daihoumaru Ship case strained relations between South Korea and Japan.
May 16 coup
From 1948, South Korea was governed by President Syngman Rhee, an anti-Communist who used the Korean War to consolidate a monopoly on political power in the republic. Rhee represented the interests of a conservative ruling class, the so-called "liberation aristocrats" who had risen to positions of influence under American occupation. These "liberation aristocrats" formed the bulk of the political class, encompassing both Rhee's supporters and his rivals in the Democratic Party, which advanced a vision of society broadly similar to his own. Rhee eliminated any significant source of real opposition, securing for example the execution of Cho Bong-am, who had campaigned against him in the presidential elections of 1956 on a platform of peaceful reunification and had attracted some 30% of the vote, an unacceptably high level of support for an opposition candidate.