South Korea’s special counsel investigation into former President Yoon Suk Yeol concluded that the Dec. 3 martial law episode was not an isolated abuse of power but the result of prolonged institutional erosion that exposed vulnerabilities in civilian oversight of the military.

The findings, released at the close of a 180-day probe on Monday, depict a presidency that gradually reframed political opposition as a security threat and drew intelligence and operational commands into domestic political calculations.

Prosecutors argue that preparations for emergency rule began early in Yoon’s term and evolved through personnel decisions, informal command channels and the securitization of