The scent of roasted meat and soju hung in the air of the Korean Army Headquarters in Seoul. Officers gathered for a dinner on the night of December 12. The acting president had been assassinated six weeks prior; the country operated under martial law, commanded by General Jeong Seung-hwa. Mid-meal, military police loyal to Major General Chun Doo-hwan, head of the Defense Security Command, entered the compound. They did not come for the meal. They seized General Jeong, accusing him of complicity in the president's murder. Troops from the 9th Division, commanded by Chun's ally Roh Tae-woo, moved into the capital, securing key positions and clashing with units loyal to the martial law commander. By dawn, Chun controlled the army without firing a single shot at his dinner guests.
The coup succeeded because it exploited a vacuum. President Park Chung-hee's murder had left a fractured military and a weak civilian government. Chun, leading an internal investigation into the assassination, used that authority to sideline rivals. His actions were a brazen subversion of the chain of command, executed with precise timing and the element of surprise. The civilian government, led by President Choi Kyu-hah, proved powerless to stop it.
This event is often seen merely as a prelude to the larger Gwangju Uprising months later. It was the decisive act. The 'December 12 Incident' secured the instrument of state power—the military—for Chun. It erased any path for a democratic transition after Park's death. The generals' dinner party ended with the table cleared for a new dictatorship. Chun would formally become president within a year, inaugurating the Fifth Republic and eight years of authoritarian rule cemented by that single night's betrayal.