The term secret police (or political police) refers to intelligence, security or police agencies that engage in covert operations against a government's political opponents and dissidents. Secret police organizations are characteristic of totalitarian regimes. Used to protect the political power of an individual dictator or an authoritarian regime, secret police often, but not always, operate outside the law and are used to repress dissidents and weaken the political opposition, frequently with violence, and torture.
Secret police originated in 18th-century Europe after the French Revolution, when such operations were established in an effort to detect any possible conspiracies or revolutionary subversion. The peak of secret-police operations in most of Europe was 1815 to 1860, "when restrictions on voting, assembly, association, unions and the press were so severe in most European countries that opposition groups were forced into conspiratorial activities." The secret police of the Austrian Empire were particularly notorious during this period. After 1860, the use of secret police declined due to increasing liberalization, except in autocratic regimes such as the Russian Empire.
In the Russian Empire, the secret police forces were the Third Section of the Imperial Chancery and then the Okhrana. After the Russian Revolution, the Soviet Union established the OGPU, NKVD, NKGB, MVD, and KGB.
In Nazi Germany, the Geheimstaatspolizei (Secret State Police, Gestapo) (1933-1945) was used to eliminate opposition; as part of the Reich Main Security Office, it also was a vital organizer of the Holocaust. Although the Gestapo had a relatively small number membership (32,000 in 1944), "it maximized these small resources through informants and a large number of denunciations from the local population." After the defeat of the Nazis, the East German secret police, the Stasi, likewise made extensive use of an extensive network of civilian informers.
Ilan Berman and J. Michael Waller describe the secret police as central to totalitarian regimes and "an indispensable device for the consolidation of power, neutralization of the opposition, and construction of a single-party state." In addition to these activities, secret police may also be responsible for tasks not related to suppressing internal dissent, such as gathering foreign intelligence, engaging in counterintelligence, organizing border security, and guarding government buildings and officials. Secret police forces sometimes endure even after the fall of a totalitarian regime.
Arbitrary detention, abduction and forced disappearance, torture, and assassination are all tools wielded by secret police "to prevent, investigate, or punish (real or imagined) opposition." Because secret police typically act with great discretionary powers "to decide what is a crime" and are a tool used to target political opponents, they operate outside the rule of law.
People apprehended by the secret police are often arbitrarily arrested and detained without due process. While in detention, arrestees may be tortured or subjected to inhumane treatment. Suspects may not receive a public trial, and instead may be convicted in a kangaroo court-style show trial, or by a secret tribunal. Secret police known to have used these approaches in history include the secret police of East Germany (the Ministry for State Security or Stasi) and Portuguese PIDE.
A single secret service may pose a potential threat to the central political authority. Political scientist Sheena Chestnut Greitens writes that: "When it comes to their security forces, autocrats face a fundamental 'coercing dilemma between empowerment and control. ... Autocrats must empower their security forces with enough coercing capacity to enforce internal order and conduct external defense. Equal important to their survival, however, they must control that capacity, to ensure it is not turned against them." Authoritarian regimes therefore attempt to engage in "coup-proofing" (designing institutions to minimize risks of a coup). Two methods of doing so are increasing fragmentation (i.e., dividing powers among the regime security apparatus to prevent "any single agency from amassing enough political power to carry out a coup") and increasing exclusivity (i.e., purging the regime security apparatus to favor familial, social, or ethnic groups perceived as more loyal).