There is no shortage of academic studies of the causes of military coups d’état which identify various factors at different levels of analysis – intra-military, societal, and international (Finer 1962; Huntington 1968; Janowitz 1964; Decalo 1976; Y.M. Kim 1985). However, the basic reason why the military not only intervenes in but dominates the politics of developing societies for considerable periods of time should be found primarily in the structure of relationships between the military and civilian sectors. Military rule in Korea illustrates clearly the almost inevitable consequence of unbalanced power relations between the military and civilian sectors following the creation of a newly independent state; with the division of the Korean Peninsula, the military was developed disproportionately to the civilian sectors.

It should thus be noted at the outset that the military was overdeveloped compared to any other sector in Korea at the time of the coup of 16 May 1961. The Korean military started as the Korean Constabulary, established by the American military government (1945-1948) for the purpose of maintaining domestic stability mainly against agitation by leftist groups. The military gained increased socio-political importance because of the division of the nation during the Occupation period. The Korean War (1950-1953) provided an important background to the military’s dominance of Korean politics, although its intervention in politics did not take place until several years after the end of the war. A major reason for this was the time-lag between the creation of the Republic and the military on the one hand and the politicisation of military officers on the other. As a result of the war, the size of the military grew to a spectacular extent (from 100 000 in 1950 to 700 000 in 1956, although it was reduced by 100 000 in 1957), but its institutional, technological, and organisational development was even more significant. Assisted by massive US aid, the military developed into the most modernised and Westernised sector in Korea during the 1950s. The civilian sectors, especially universities and the bureaucracy, were also experiencing modernisation, but they were less organised and less modern in outlook, smaller in size, and limited in political and economic participation (Lee 1968:150). Later, with rapid industrialisation, the civilian sectors modernised more rapidly than the military, but reversing the military’s political dominance, once it had taken root, proved complicated and time-consuming, as was tragically manifested in the Kwangju Uprising of 1980.

At a societal level, the political situation created the structural conditions for long-term military rule in Korea: the Republic was founded upon an imported ideology of liberal democracy, but Korea’s political tradition lacked experience of this Western system; as a result, liberal democracy quickly degenerated into the authoritarianism of Rhee Syngman’s 1948-1960 patrimonial rule. The effort of the succeeding Chang Myon government to re-establish a democratic system was bound to fail because its leadership could not control the political turbulence created by the April Uprising of 1960 which toppled the Rhee regime. Imposing liberal democracy upon an unprepared nation simply did not work. What it did was to provide the basis for the emergence of military rule, initiated by younger officers who denied the idea of liberal democracy entirely and instead sought single-mindedly the objectives of economic growth and effective leadership. The coup which took place on 16 May 1961 cannot be fully understood without considering the coup leaders’ motivations, which stemmed from the political discontent over the lack of opportunities for promotion and specific political circumstances created after the April Uprising. However, even if those conditions had not occurred, it seems likely that the Korean military would have taken a major role in politics at some time.

In a sense, the coup of 1961 proved to be an historical turning point which temporarily put an end to political struggles amongst the diverse forces which sought to fulfil different objectives of ‘nation building’ in the newly independent country. In this struggle, the military’s alternative – capitalist industrialisation combined with authoritarian control – gained supremacy and dominated Korean society for some time.