Military counterintelligence of the Soviet Army

Military counterintelligence of the Soviet Armed Forces was controlled by the nonmilitary Soviet secret police throughout the history of the USSR.

The military counterintelligence departments of the Soviet Armed Forces existed at all larger military formations and were called Special Departments (Особый отдел (ОсО)) or third departments/sections. The staff of the Special Department would usually establish a secret network of informants.

TGU (ТГУ КГБ СССР, 3 ГУ КГБ СССР ('third')) functionaries were responsible for protection of the military units, important servicemen (e.g. commanding officers) against activities of foreign military attaché offices diplomats.

Timeline

 * Initially there was no common counterintelligence directorate. Various Armies and Fronts had their "Special Departments".
 * Military Department of Vecheka, Военный отдел ВЧК
 * Special Department of Vecheka, Особый отдел ВЧК,
 * Special Department of Secret Operative Directorate of GPU NKVD RSFSR, Особый отдел СОУ (Секретно-оперативное управление) ГПУ, July 1922
 * Special Department of OGPU, Особый отдел ОГПУ, September 1930
 * 4th Division of the OGPU Special Department, 4 отделение Особого отдела ОГПУ
 * Special Department of the GUGB NKVD USSR, Особый отдел ГУГБ НКВД СССР (July 1934 –)
 * 5th (Special) Dept. of GUGB, 5-й (особый) отдел ГУГБ December 1936 –
 * 2nd Directorate of NKVD (Special Departments), 2-е Управление (особых отделов) НКВД СССР June 1938 –
 * 4th (Special) Dept. of GUGB, 4-й (особый) отдел ГУГБ September 1938 – Feb. 1941
 * 3rd Directorate of People's Commissariat of Defense,(UKR НКО) Третье Управление НКО February 1941 – July 1941
 * 3rd Directorate of People's Commissariat of Soviet Navy (UKR NKВМФ), Третье Управление НКВМФ February 1941 – January 1942
 * 3rd Dept. of NKVD, (OKR NKVD) Третий отдел НКВД February 1941 – Jul. 1941
 * Directorate of Special Departments of NKVD, (УОО НКВД) Управление особых отделов НКВД СССР July 1941 – April 1943
 * SMERSH (ГУРК НКО) 1943–1946
 * Third Chief Directorate of MGB of the USSR, Третье Главное Управление МГБ СССР, May 1946 – 1953
 * Third Directorate of MVD of the USSR, Третье управление МВД СССР, March 1953 – 1954
 * Third Chief Directorate of KGB by the Council of Ministers of the USSR, Третье главное управление КГБ при СМ СССР, March 1954 – 1960
 * Third Directorate of KGB by the Council of Ministers of the USSR, Третье управление КГБ при СМ СССР, 1960–1978
 * Third Directorate of KGB of the USSR, Третье управление КГБ СССР, 1978–1982
 * Third Chief Directorate of KGB of the USSR, Третье главное управление КГБ СССР, 1982–1991