information:extraction, structural:scholar_edition, linguistic:paraphrasing
Rise to power

On April 26, 1960, Syngman Rhee, the authoritarian inaugural President of South Korea, was forced out of office and into exile following the April Revolution, a student-led uprising. Yun Po-sun was elected as president later that year on July 29, although the real power was held by Prime Minister Chang Myon. Problems arose immediately because neither man could command loyalty from any majority of the Democratic Party or reach agreement on the composition of the cabinet. Prime Minister Chang attempted to hold the tenuous coalition together by reshuffling cabinet positions three times within five months.

Meanwhile, the new government was caught between an economy that was suffering from a decade of mismanagement and corruption under the Rhee presidency and the students who had instigated Rhee's ousting. Protesters regularly filled the streets making numerous and wide-ranging demands for political and economic reforms. Public security had deteriorated while the public had distrusted the police, which was long under the control of the Rhee government, and the ruling Democratic Party lost public support after long factional fighting.

Against this backdrop of social instability and division, Major General Park formed the Military Revolutionary Committee. When he found out that he was going to be retired within the next few months, he sped up the committee's plans. It led a military coup on May 16, 1961, which was nominally led by Army Chief of Staff Chang Do-yong after his defection on the day it started. On May 18, Chang Myon announced his resignation along with his cabinet. Yun accepted the coup and persuaded the United States Eighth Army and the commanders of various ROK army units not to interfere with the new government.

Initially, a new administration was formed from among those military officers who supported Park. The reformist military Supreme Council for National Reconstruction was nominally led by General Chang. Following Chang's arrest in July 1961, Park took overall control of the council. The coup was largely welcomed by a general populace exhausted by political chaos.

Soon after the coup, Park was promoted to Lieutenant General. The South Korean historian Hwang Moon Kyung described Park's rule as very "militaristic", noting right from the start Park aimed to mobilize South Korean society along "militaristically disciplined lines". One of Park's very first acts upon coming to power was a campaign to "clean up" the streets by arresting and putting the homeless to work in "welfare centers".

The American historian Carter Eckert wrote that the historiography, including his work, around Park has tended to ignore the "enormous elephant in the room" namely that the way in which Park sought kündaehwa (modernization) of South Korea was influenced by his distinctively militaristic way of understanding the world, and the degree in which the Japanophile Park was influenced by Japanese militarism as he created what South Korean historians call a "developmental dictatorship". Eckert called South Korea under Park's leadership one of the most militarized states in the entire world, writing that Park sought to militarize South Korean society in a way that no other South Korean leader has ever attempted.

In the Imperial Japanese Army, there was the belief that bushido would give Japanese soldiers enough "spirit" as to make them invincible in battle, as the Japanese regarded war as simply a matter of willpower with the side with the stronger will always prevailing. Reflecting his background as a man trained by Japanese officers, one of Park's favorite sayings was "we can do anything if we try" as Park argued that all problems could be overcome by sheer willpower. Eckert wrote when interviewing Park's closest friends, he always received the same answer when he asked them what was the important influence on Park, namely his officer training by the Japanese in Manchukuo. All of Park's friends told Eckert that to understand him, one needed to understand his Ilbonsik sagwan kyoyuk (Japanese officer training) as they all maintained Park's values were those of an Imperial Japanese Army officer.

On June 19, 1961, the military council created the Korean Central Intelligence Agency in order to prevent counter-coups and suppress potential enemies, both foreign and domestic. Along with being given investigative powers, the KCIA was also given the authority to arrest and detain anyone suspected of wrongdoing or having anti-government sentiments. Under its first director, retired Brigadier General Kim Jong-pil, a relative of Park and one of the original planners of the coup, the KCIA would extend its power to economic and foreign affairs.

President Yun remained in office, giving the military regime legitimacy. After Yun resigned on March 24, 1962, Lt. General Park, who remained chairman of the Supreme Council for National Reconstruction, consolidated his power by becoming acting president; he was also promoted to full general. Park agreed to restore civilian rule following pressure from the Kennedy administration.

In 1963, he was elected president in his own right as the candidate of the newly created Democratic Republican Party. He appointed Park Myung-keun, the Vice Leader of the party as the chief of the President's Office. He narrowly defeated former President Yun, the candidate of the Civil Rule Party, by just over 156,000 votes—a margin of 1.5 percent. Park would be re-elected president in 1967, defeating Yun with somewhat less difficulty.