When Park sent troops to the war in Vietnam, Mr. Chun commanded an infantry division, and he subsequently was named to Park’s security-and-intelligence team. Then one night in October 1979, Park was assassinated by the president’s disgruntled spy chief at a drunken party. A new president, Choi Kyu Hah, was appointed, but he was widely deemed ineffectual. Within two months, Mr. Chun was launching a takeover — but not for the presidency.
