Joint State Political Directorate in the context of "Vorkutlag"

The People's Commissariat for Internal Affairs (Russian: Народный комиссариат внутренних дел, romanized: Narodnyy komissariat vnutrennikh del, IPA: [nɐˈrodnɨj kəmʲɪsərʲɪˈat ˈvnutrʲɪnʲɪɣ dʲel]), abbreviated as NKVD (Russian: НКВД; listen), was the interior ministry and secret police of the Soviet Union from 1934 to 1946. The agency was formed to succeed the Joint State Political Directorate (OGPU) secret police organization, and thus had a monopoly on intelligence and state security functions. The NKVD is known for carrying out political repression and the Great Purge under Joseph Stalin, as well as counterintelligence and other operations on the Eastern Front of World War II. The head of the NKVD was Genrikh Yagoda from 1934 to 1936, Nikolai Yezhov from 1936 to 1938, Lavrentiy Beria from 1938 to 1946, and Sergei Kruglov in 1946.

First established in 1917 as the NKVD of the Russian SFSR, the ministry was tasked with regular police work and overseeing the country's prisons and labor camps. It was disbanded in 1930, and its functions dispersed among other agencies before being reinstated as a commissariat of the Soviet Union in 1934. During the Great Purge in 1936–1938, on Stalin's orders, the NKVD conducted mass arrests, imprisonment, torture, and executions of hundreds of thousands of Soviet citizens. The agency sent millions to the Gulag system of forced labor camps and, during World War II, carried out the mass deportations of hundreds of thousands of Poles, Balts, and Romanians, and millions of ethnic minorities from the Caucasus, to remote areas of the country, resulting in millions of deaths. Hundreds of thousands of NKVD personnel served in Internal Troops divisions in defensive battles alongside the Red Army, as well as in "blocking formations," preventing retreat. The agency was responsible for foreign assassinations, including that of Leon Trotsky.

The Gulag was a system of forced labor camps in the Soviet Union. The word Gulag originally referred only to the division of the Soviet secret police that was in charge of running the forced labor camps from the 1930s to the early 1950s during Joseph Stalin's rule, but in English literature the term is popularly used for the system of forced labor throughout the Soviet era. The abbreviation GULAG (ГУЛАГ) stands for "Glávnoye upravléniye ispravítel'no-trudovýkh lageréy " (Гла́вное управле́ние исправи́тельно-трудовы́х лагере́й or "Main Directorate of Correctional Labour Camps"), but the full official name of the agency changed several times.

The Gulag is recognized as a major instrument of political repression in the Soviet Union. The camps housed both ordinary criminals and political prisoners, a large number of whom were convicted by simplified procedures, such as NKVD troikas or other instruments of extrajudicial punishment. The agency was established in 1930 and initially was administered by the OGPU (1923–1934), later known as the NKVD (1934–1946) and the Ministry of Internal Affairs (MVD) in the final years.

The Committee for State Security (Russian: Комитет государственной безопасности, romanized: Komitet gosudarstvennoy bezopasnosti, IPA: [kəmʲɪˈtʲed ɡəsʊˈdarstvʲɪn(ː)əj bʲɪzɐˈpasnəsʲtʲɪ]), abbreviated as KGB (Russian: КГБ, IPA: [ˌkɛɡɛˈbɛ]; listen to both) was the main security agency of the Soviet Union from 1954 to 1991. It was the direct successor of preceding Soviet secret police agencies including the Cheka, OGPU, and NKVD. Attached to the Council of Ministers, it was the chief government agency of "union-republican jurisdiction", carrying out internal security, foreign intelligence, counter-intelligence and secret police functions. Similar agencies operated in each of the republics of the Soviet Union aside from the Russian SFSR, where the KGB was headquartered, with many associated ministries, state committees and state commissions.

The agency was a military service governed by army laws and regulations, in the same fashion as the Soviet Army or the MVD Internal Troops. While most of the KGB archives remain classified, two online documentary sources are available. Its main functions were foreign intelligence, counter-intelligence, operative-investigative activities, guarding the state border of the USSR, guarding the Soviet leadership, preserving the security of government communications as well as combating dissident and separatism within Soviet society.

The State Political Directorate (Russian: Государственное политическое управление, romanized: Gosudarstvennoye politicheskoye upravleniye), abbreviated as GPU (Russian: ГПУ), was the secret police of the Russian Soviet Federative Socialist Republic from February 1922 to November 1923. It was the immediate successor of the Cheka, and was replaced by the Joint State Political Directorate (OGPU).

Chekism (Russian: Чекизм) was the form of counterintelligence state widely present in the Soviet Union by which secret police, counterintelligence and internal security services (originally the Cheka, hence the name, but most famously the KGB) strongly controlled all spheres of society. Similar circumstances exist in some post-Soviet states, particularly Russia. The term encompasses both the ideological underpinnings justifying often arbitrary repression as well as the political situation where security service members occupy high-level political offices and a lack of civilian control over their activities (in extreme cases, the opposite). The term is sometimes also applied to other Eastern Bloc security services (long-serving East German security chief Erich Mielke was fond of calling himself a Chekist), and, presently, to the federal government of Russia under Vladimir Putin (himself a former KGB officer).

The name is derived from Cheka, the colloquial name of the first in the succession of Soviet secret police agencies. Officers of the succession of security agencies (Cheka, GPU, OGPU, NKVD, GUGB, NKGB, MGB, MVD, and, longest-lasting, the KGB), as well as their Russian successors, the Federal Security Service, are often referred to, both by themselves and by the broader public, as "Chekists".