OSA meaning in Military and Defence ?

The Office of Special Affairs (OSA), formerly the Guardian's Office, is a department of the Church of Scientology International. According to the Church, the OSA is responsible for directing legal affairs, public relations, pursuing investigations, publicizing the Church's "social betterment works," and "oversee[ing its] social reform programs". Some observers outside the Church have characterized the department as an intelligence agency, comparing it variously to the CIA or the KGB. The department has targeted critics of the Church with dead agent operations and character assassination.

OSA is the successor to the now-defunct Guardian's Office, which was responsible for Operation Snow White and Operation Freakout; both are in Department 20 in the Scientology organizational chart. The most recent head of OSA International was Mike Rinder, who has since departed from the organization and criticizes it severely, appearing as a co-host on Leah Remini: Scientology and the Aftermath.