Political cleansing of population in the context of "Purge"

Political repression is the act of a state entity controlling a citizenry by force for political reasons, particularly for the purpose of restricting or preventing the citizenry's ability to take part in the political life of a society, thereby reducing their standing among their fellow citizens. Repression tactics target the citizenry who are most likely to challenge the political ideology of the state in order for the government to remain in control. In autocracies, the use of political repression is to prevent anti-regime support and mobilization. It is often manifested through policies such as human rights violations, surveillance abuse, police brutality, kangaroo courts, imprisonment, involuntary settlement, stripping of citizen's rights, lustration, and violent action or terror such as murder, summary executions, torture, forced disappearance, and other extrajudicial punishment of political activists, dissidents, or the general population. Direct repression tactics are those targeting specific actors who become aware of the harm done to them while covert tactics rely on the threat of citizenry being caught (wiretapping and monitoring). The effectiveness of the tactics differs: covert repression tactics cause dissidents to use less detectable opposition tactics while direct repression allows the citizenry to witness and react to the repression. Political repression can also be reinforced by means outside of written policy, such as by public and private media ownership and by self-censorship within the public.

Where political repression is sanctioned and organised by the state, it may constitute state terrorism, genocide, politicide or crimes against humanity. Systemic and violent political repression is a typical feature of dictatorships, totalitarian states and similar regimes. While the use of political repression varies depending on the authoritarian regime, it is argued that repression is a defining feature and the foundation of autocracies by creating a power hierarchy between the leader and citizenry, contributing to the longevity of the regime. Repressive activities have also been found within democratic contexts as well. This can even include setting up situations where the death of the target of repression is the result. If political repression is not carried out with the approval of the state, a section of government may still be responsible. Some examples are the COINTELPRO operations by the FBI from 1956 to 1971 and the Palmer Raids from 1919 to 1920.

From October of 1965 to March of 1966, a series of large-scale killings and civil unrest primarily targeting members and supposed sympathizers of the Communist Party of Indonesia (PKI) were carried out in Indonesia. Other affected groups included alleged communist sympathisers, Gerwani women, trade unionists, ethnic Javanese Abangan, ethnic Chinese, atheists, accused "kafir" (unbelievers in Islam), and alleged leftists in general. According to the most widely published estimates, at least 500,000 to 1 million people were killed. Some of the higher estimates reach figures as much as 2 to 3 million. The atrocities, sometimes described as a genocide or a politicide, were instigated by the Indonesian Army under Suharto. Research and declassified documents demonstrate the Indonesian authorities received support from foreign countries such as the United States and the United Kingdom.

The killings began as an anti-communist purge following a so-called attempted coup d'état by the 30 September Movement. It was a pivotal event in the transition to the "New Order" and the elimination of PKI as a political force, with impacts on the global Cold War. The Army, after banning all independent news source from issuing for a week, almost at once pinned the abortive coup attempt to the PKI. Additionally, the intelligence agencies of the United States, United Kingdom and Australia engaged in black propaganda campaigns against Indonesian communists. During the Cold War, the U.S., its government, and its Western allies had the goal of halting the spread of communism and bringing countries into the sphere of Western Bloc influence. Britain had additional reasons for seeking Sukarno's removal, as his government was involved in an undeclared war with neighbouring Malaysia, a Commonwealth federation of former British colonies.