Jang Do-young

Jang initially served in the Imperial Japanese Army during the Japanese occupation of Korea, and retired from the Japanese army after liberation with the rank of lieutenant. He was then commissioned into the army as a South Korean military officer. After serving as the commander of the 5th and 9th regiments, and as the head of the Army Counter Intelligence Corps, he commanded the 6th Infantry Division's forces, and during the initial stages of the Korean war his forces were defeated by Chinese forces at the battles of Sachang-ni, Hwacheon-gun, and Gangwon-do during the initial stages of the Chinese spring offensive. However, his forces quickly recovered and subsequently defeated the Chinese forces at the battle of Yongmunsan, making up for the defeat of the previous month.[5]

Jang Do-young giving a speech 4 days after the coup. Park Chung-hee is on the right side of the photo.

After the armistice, Jang became Army Chief of Staff at the age of 39 under the Cabinet of Chang Myon following the April 19 Revolution in 1960, but he was not loyal to his government. Jang first learned of the coup from Park Chung Hee on 10 April 1961, who wanted him to lead the new government so that the entire military would support it. He responded by neither joining the plotters nor notifying the government.[6] This indecisiveness has been seen as giving legitimacy to the coup. In addition, Jang later convinced then-prime minister Chang Myon, that a security report containing leaked details of the coup (when it was scheduled to occur on May 12) was unreliable. This allowed the planners to postpone it to May 16.[7]

After the coup, Jang was appointed as a figurehead leader while Park held the real power.[8] Soon afterwards, however, he formed a small faction of moderates, causing conflict with other more militarist officers, including Park.[9] At his peak, Jang occupied four positions: chairman of the Supreme Council, prime minister, defense minister, and army chief of staff.[10] Through May 1961, he attempted to gain recognition of the new government from the United States, meeting with John F. Kennedy on 24 May and promising a transfer to civilian control by 15 August (a priority for the US and president in name only Yun Posun, who Jang wanted to remain in office[11]) on 31 May. These moves quickly made him unpopular with the rest of the military leaders, who saw him as a threat to their power and the goals of the coup.[12] In June, after winning the acceptance of the US, Park and his followers turned the tide against Jang by implementing laws to restrict his influence. On July 3, Jang, the ten MPs posted around him for security, and forty-four other officers were arrested on charges of conspiring to execute a countercoup.[10][12] He surrendered without any resistance.[12]

• Kim, Byung-Kook; Vogel, Ezra F. (2011). The Park Chung Hee Era: The Transformation of South Korea. Harvard University Press.