Left-wing terrorism or far-left terrorism (sometimes called Marxist–Leninist terrorism or revolutionary/left-wing terrorism) is terrorism meant to overthrow capitalist systems and replace them with Marxist–Leninist or socialist societies. Left-wing terrorism also occurs within already socialist states as activism against the current ruling government. It has taken vivid manifestations across the world and presented diverging dynamics and relationships with national governments and political economies.
Most left-wing terrorist groups that had operated in the 1970s and 1980s disappeared by the mid-1990s. One exception was the Greek Revolutionary Organization 17 November (17N), which lasted until 2002. Since then, left-wing terrorism has been minor compared with other forms such as right-wing terrorism, and is mostly carried out by insurgent groups in the developing world.
Left-wing terrorists have been influenced by various communist and socialist currents, including Marxism. Narodnaya Volya, a 19th-century terrorist group that killed Tsar Alexander II of Russia in 1881 and developed the concept of propaganda by the deed, is a major influence.
According to Sarah Brockhoff, Tim Krieger and Daniel Meierrieks, while left-wing terrorism is ideologically motivated, nationalist-separatist terrorism is ethnically motivated. They argue that the revolutionary goal of left-wing terrorism is non-negotiable whereas nationalist terrorists are willing to make concessions. They suggest that rigidity of the demands of left-wing terrorists may explain their lack of support relative to nationalist groups. Nevertheless, many on the revolutionary left have showed solidarity for national liberation groups employing terrorism, such as Irish nationalists, the Palestine Liberation Organization and the South American Tupamaros, seeing them as engaged in a global struggle against capitalism. Since nationalist sentiment is fueled by socio-economic conditions, some separatist movements, including the Basque ETA, the Provisional Irish Republican Army and the Irish National Liberation Army incorporated communist and socialist ideology into their policies.
David Brannan writes that left-wing terrorists and insurgents tend not to engage in indiscriminate attacks on the public as it not only runs contrary to the socialist ideals they espouse of being protectors of the working class, but they also do not want to alienate large swaths of the working population as such organizations and individuals seek to gain their support.
Left-wing terrorism has its roots in 19th and early 20th century anarchist terrorism and became pronounced during the Cold War. Modern left-wing terrorism developed in the context of the political unrest of 1968. In Western Europe, notable groups included the West German Red Army Faction (RAF), the Italian Red Brigades, the French Action Directe (AD) and the Belgian Communist Combatant Cells (CCC). Asian groups have included the Japanese Red Army and the Liberation Tigers of Tamil Eelam, although the latter organization later adopted nationalist terrorism. In Latin America, groups that became actively involved in terrorism in the 1970s and 1980s included the Nicaraguan Sandinistas, the Peruvian Shining Path and the Colombian 19th of April Movement.
The Front de libération du Québec was a Marxist–Leninist group active in Canada in the 1960s and '70s, promoting socialist insurrection and an independent Quebec. They are known for over 160 bombings and other violent incidents that killed eight, and for the kidnap-murder of Quebec politician Pierre Laporte in 1970.
Modern left-wing terrorist groups in the United States developed from remnants of the Weather Underground and extremist elements of the Students for a Democratic Society. Between 1973 and 1975, the Symbionese Liberation Army was active, committing bank robberies, murders, and other acts of violence. Other terrorist groups such as the small New World Liberation Front resorted to death threats, drive-by shootings and planting of pipe-bombs in the late 1970s. During the 1980s, both the May 19th Communist Organization (M19CO) and the smaller United Freedom Front were active. After 1985, following the dismantling of both groups, one source reports there were no confirmed acts of left-wing terrorism by similar groups. Incidents of left-wing terrorism dropped off at the end of the Cold War (circa 1989), partly due to the loss of support for communism.
Stefan M. Aubrey describes the Sandinistas, Shining Path, 19th of April Movement, and Revolutionary Armed Forces of Colombia (FARC) as the main organizations involved in left-wing terrorism in Latin America during the 1970s and 1980s. These organizations opposed the United States government and drew local support as well as receiving support from the Soviet Union and Cuba.
The Revolutionary Armed Forces of Colombia (FARC) is a Marxist–Leninist organization in Colombia which has engaged in vehicle bombings, gas cylinder bombs, killings, landmines, kidnapping, extortion and hijacking as well as guerilla and conventional military. The United States Department of State includes the FARC-EP on its list of foreign terrorist organizations, as does the European Union. It funds itself primarily through extortion, kidnapping and their participation in the illegal drug trade. Many of their fronts enlist new and underage recruits by force, distribute propaganda and rob banks. Businesses operating in rural areas, including agricultural, oil, and mining interests, were required to pay "vaccines" (monthly payments) which "protected" them from subsequent attacks and kidnappings. An additional, albeit less lucrative, source of revenue was highway blockades in which guerrillas stopped motorists and buses in order to confiscate jewelry and money. An estimated 20 to 30 percent of FARC combatants are under 18 years old, with many as young as 12 years old, for a total of around 5000 children. Children who try to escape the ranks of the guerrillas are punished with torture and death.
The May 19th Communist Organization, also referred to as the May 19 Communist Coalition, was a United States-based, self-described revolutionary organization formed by splintered-off members of the Weather Underground and the Black Liberation Army. The M19CO name was derived from the birthdays of Ho Chi Minh and Malcolm X. The May 19 Communist Organization was active from 1978 to 1985. It also included members of the Black Panthers and the Republic of New Africa (RNA). According to a 2001 US government report, the alliance between Black Liberation Army and Weather Underground members had three objectives: free political prisoners from US prisons; appropriate capitalist wealth (through armed robberies) to fund their operations; and initiate a series of bombings and terrorist attacks against the United States.
The Communist Party of Peru, more commonly known as the Shining Path, is a Maoist guerrilla organization that launched the internal conflict in Peru in 1980. Widely condemned for its brutality, including violence deployed against peasants, trade union organizers, popularly elected officials and the general civilian population, Shining Path is on the United States Department of State's "Designated Foreign Terrorist Organizations" list. Peru, the European Union, and Canada likewise regard Shining Path as a terrorist group and prohibit providing funding or other financial support.
Stefan M. Audrey describes the Japanese Red Army and the Liberation Tigers of Tamil Eelam (LTTE) as the main left-wing terrorist organizations in Asia, although he notes that the LTTE later transformed into a nationalist terrorist organization.
Armed Naxalite groups operate across large parts of the central and eastern rural regions of India. Informed by the People's War strategy of Maoism, the most prominent of the groups is the Communist Party of India (Maoist), formed through the merging of two previous Naxalite organizations, the People's War Group and the Maoist Communist Centre of India (MCC). Armed Naxalite movements are considered India's largest internal security threat. Naxalite militants have engaged in numerous terrorist attacks and human rights violations in India's Red Corridor. A Frontline magazine article calls the Bhamragad Taluka, where the Madia Gond Adivasis live, the heart of the Naxalite-affected region in Maharashtra.
The Communist Party of Nepal (Maoist) has been responsible for hundreds of attacks on government and civilian targets.
After the United People's Front of Nepal (UPF)'s Maoist wing, CPN-M, performed poorly in elections and was excluded from the 1994 election, the Maoists turned to insurgency. They aimed to overthrow Nepal's monarchy and parliamentary democracy, and to change Nepalese society, including a purge of the nation's elite class, a state takeover of private industry, and collectivization of agriculture. In Nepal, attacks against civilian populations occurred as part of Maoist strategy, leading Amnesty International to state:
The CPN (Maoist) has consistently targeted private schools, which it ideologically opposes. On the 14 April 2005 the CPN (Maoist) demanded that all private schools shut down, although this demand was withdrawn on 28 April. Following this demand, it bombed two schools in western Nepal on 15 April, a school in Nepalganj, Banke district on 17 April and a school in Kalyanpur, Chitwan on 21 April. CPN (Maoist) cadres also reportedly threw a bomb at students taking classes in a school in Khara, Rukum district.
The Japanese Red Army (JRA) was founded in 1969 as the "Red Army Faction" by students impatient with the Communist Party. In 1970, they hijacked a plane to North Korea, where nine of their members were interned. Fourteen members were killed during an internal purge. In 1971, the renamed JRA formed a connection with the Popular Front for the Liberation of Palestine and established a base in Lebanon. Their major terrorist acts included an armed attack on the Tel Aviv airport, hijacking planes to Libya and Bangladesh, kidnapping the French ambassador to the Hague, and bombing a United Service Organizations (USO) nightclub in Naples, Italy. By the mid-1990s, their level of activity had declined and the US State Department no longer considered them a terrorist threat. In 2001, their leader announced the dissolution of the group, although some of its members were in prison and others were still wanted by police.
Left-wing groups like the Pakhtoon Zalmay, Al-Zulfiqar organisation (AZO) and the MQM including its predecessor the Muhajir Qaumi Movement committed numerous acts of violence including bombings, targeted killings, disinformation and assassinations.  
Typically small and urban-based, left-wing terrorist organizations in Europe have been committed to overthrowing their countries' governments and replacing them with regimes guided by Marxist–Leninist ideology. Although none have achieved any degree of success in accomplishing their goals, they have caused serious security problems in Germany, Belgium, Italy, Greece, France, Turkey, Portugal and Spain.
Action Directe (AD) was active in France between 1979 and 1987. Between 1979 and 1985, they concentrated on non-lethal bombings and strafings of government buildings, although they assassinated a French Ministry of Defense official. Following arrests of some of its members, the organization declined and became inactive. The French government has banned the group.
The Communist Combatant Cells (CCC) was founded in 1982 in Belgium by Pierre Carette. With about ten members, the CCC financed its activities through a series of bank robberies. Over the course of 14 months, they carried out 20 attacks against property, mostly North Atlantic Treaty Organization (NATO) facilities. Despite attempts to avoid loss of life, there were casualties as a result of these attacks. After Carette and other members were arrested in 1985, the group ceased to be operational. Carette served 17 years of a life sentence, although his colleagues that were convicted with him were released earlier.
The First of October Anti-Fascist Resistance Groups (GRAPO) was a Maoist terrorist group in Spain that was founded in 1975. Since its inception 2007, it assassinated 84 people, including police, military personnel, judges and civilians; either by bombings or shootings. The group has committed a number of kidnappings, initially for political reasons, later on, mainly for extortion. Its last attack was committed in 2006, when GRAPO militants shot dead Ana Isabel Herrero, the owner of a temporary work agency in Zaragoza.
The Irish People's Liberation Organisation (IPLO) was a small Irish republican Revolutionary socialist paramilitary organisation which was formed in 1986 by disaffected and expelled members of the Irish National Liberation Army (INLA). It carried out paramilitary/guerrilla style attacks in Northern Ireland between 1986 - 1992 until the Provisional IRA destroyed the group.
Some of the IPLO's most notable attacks during its existence were the following:
The Popular Forces 25 April (FP-25) was formed in Portugal under the leadership of Lt. Col. Otelo Saraiva de Carvalho. Named after the 1974 military coup that overthrew the right-wing regime that had ruled Portugal since 1926, FP-25 aimed to overthrow the Portuguese government and establish a Marxist state. It carried out a series of assassinations and bombing attacks against the Portuguese government. They ceased activity in the mid 1980s.
The Red Army Faction (RAF), which developed out of the Baader-Meinhof Group in Germany, carried out a series of terrorist attacks in the 1970s and remained active for over 20 years. The RAF was organized into small isolated cells, and had connections with the Popular Front for the Liberation of Palestine and Carlos the Jackal. Although the group's leaders, including Gudrun Ensslin, Andreas Baader and Ulrike Meinhof were arrested in 1972, it carried out major attacks, including kidnapping and hijacking. On April 7, 1977 unknown RAF members assassinated a Prosecutor-General, Siegfried Buback, a former Nazi.
The Red Brigades were founded in August 1970, mostly by former members of the Communist Youth movement who had been expelled from the parent party for extremist views. The largest terrorist group in Italy, its aim was to overthrow the government and replace it with a communist system.
The Revolutionary Organization 17 November, also known as 17N or N17, was a long-lasting urban terrorist organization named in commemoration of a 1973 mass demonstration and riot against the military junta. Since 2001, the group had killed 23 people, including U.S. officials, NATO officials and Greek politicians, magistrates and businessmen. Attempts by the Greek police, the Central Intelligence Agency (CIA), and Scotland Yard to investigate the group were unsuccessful. The group was captured in 2002, after one of its members was wounded by a bomb he was carrying. It has been recognized as a terrorist organization by the Greek State, the US and international law enforcement agencies.
The Revolutionary People's Liberation Party/Front is a militant Marxist–Leninist party in Turkey. The US, UK and EU categorize it as a terrorist organization. As of 2007, the Counter-Terrorism and Operations Department of Directorate General for Security list it among the 12 active terrorist organizations in Turkey. It is one of the 44 names listed in the 2008 U.S. State Department list of Foreign Terrorist Organizations, one of the 48 groups and entities to which the EU's Common Position 2001/931/CFSP on the application of specific measures to combat terrorism applies and one of the 45 international terrorist organisations in the list of Proscribed Terrorist Groups of the UK Home Office.