The Salvadoran Civil War () was a twelve-year civil war in El Salvador that was fought between the government of El Salvador that was backed by the United States, against the Farabundo Martí National Liberation Front (FMLN), a coalition of left-wing guerrilla groups that was backed by Cuba under Fidel Castro and the Soviet Union. A coup on 15 October 1979 followed by government killings of anti-coup protesters is widely seen as the start of the civil war. The war did not formally end until after the collapse of the Soviet Union, when, on 16 January 1992 the Chapultepec Peace Accords were signed in Mexico City.

The United Nations (UN) reports that the war killed more than 75,000 people between 1979 and 1992, along with approximately 8,000 disappeared persons. Human rights violations, particularly the kidnapping, torture, and murder of suspected FMLN sympathizers by state security forces and paramilitary death squads, were pervasive.

The Salvadoran government was considered an ally of the U.S. in the context of the Cold War. During the Carter and Reagan administrations, the US provided economic aid to the Salvadoran government. The US also provided significant training and equipment to the military. By May 1983, it was reported that US military officers were working within the Salvadoran High Command and making important strategic and tactical decisions. The United States government believed its extensive assistance to El Salvador's government was justified on the grounds that the insurgents were backed by the Soviet Union.

Counterinsurgency tactics implemented by the Salvadoran government often targeted civilians. Overall, the United Nations estimated that FMLN guerrillas were responsible for 5 percent of atrocities committed during the civil war, while 85 percent were committed by the Salvadoran security forces. Accountability for these civil war-era atrocities has been hindered by a 1993 amnesty law. In 2016, however, the Supreme Court of Justice of El Salvador ruled in case Incostitucionalidad 44-2013/145-2013 that the law was unconstitutional and that the Salvadoran government could prosecute suspected war criminals.

Background El Salvador has historically been characterised by extreme socioeconomic inequality. In the late 19th century, coffee became a major cash crop for El Salvador. The divide between rich and poor grew through the 1920s and was compounded by a drop in coffee prices following the stock-market crash of 1929. In 1932, the Central American Socialist Party was formed and led an uprising of peasants and Indigenous people against the government. The later-formed FMLN was named after Farabundo Martí, one of the leaders of the uprising. The rebellion was brutally suppressed in La Matanza, during which approximately 30,000 civilians were murdered by the armed forces. La Matanza – 'the slaughter' in Spanish, as it came to be known – allowed military dictatorships to monopolize political power in El Salvador while protecting the economic dominance of the landowning elite. Opposition to this arrangement among middle-class, working-class, and poor Salvadorans grew throughout the 20th century.

On 14 July 1969, an armed conflict erupted between El Salvador and Honduras over immigration disputes caused by Honduran land reform laws. The conflict (known as the Football War) lasted only four days but had major long-term effects for Salvadoran society. Trade was disrupted between El Salvador and Honduras, causing tremendous economic damage to both nations. An estimated 300,000 Salvadorans were displaced due to battle, many of whom were exiled from Honduras; in many cases, the Salvadoran government could not meet their needs. The Football War also strengthened the power of the military in El Salvador, leading to heightened corruption. In the years following the war, the government expanded its purchases of arms from sources such as Israel, Brazil, West Germany and the United States.

The 1972 Salvadoran presidential election was marred by massive electoral fraud, which favored the military-backed National Conciliation Party (PCN), whose candidate Arturo Armando Molina was a colonel in the Salvadoran Army. Opposition to the Molina government was strong on both the right and the left. Also in 1972, the Marxist–Leninist Fuerzas Populares de Liberación Farabundo Martí (FPL) – established in 1970 as an offshoot of the Communist Party of El Salvador – began conducting small-scale guerrilla operations in El Salvador. Other organizations such as the People's Revolutionary Army (ERP) also began to develop.

The growth of left-wing insurgency in El Salvador occurred against a backdrop of rising food prices and decreased agricultural output exacerbated by the 1973 oil crisis. This worsened the existing socioeconomic inequality in the country, leading to increased unrest. In response, President Molina enacted a series of land reform measures, calling for large landholdings to be redistributed among the peasant population. The reforms failed, thanks to opposition from the landed elite, reinforcing the widespread discontent with the government.

On 20 February 1977, the PCN defeated the National Opposition Union (UNO) in the presidential elections. As was the case in 1972, the results of the 1977 election were fraudulent and favored a military candidate, General Carlos Humberto Romero. State-sponsored paramilitary forces – such as the infamous Organización Democrática Nacionalista (ORDEN) – reportedly strong-armed peasants into voting for the military candidate by threatening them with machetes.Armstrong, Robert / Shenk, Janet. El Salvador: The Face of Revolution (Boston: South End Press, 1982), 163. The period between the election and the formal inauguration of President Romero on 1 July 1977 was characterized by massive protests from the popular movement, which were met by state repression. On 28 February 1977, a crowd of political demonstrators gathered in downtown San Salvador to protest the electoral fraud. Security forces arrived on the scene and opened fire, resulting in a massacre as they indiscriminately killed demonstrators and bystanders alike. Estimates of the number of civilians killed range between 200 and 1,500. President Molina blamed the protests on "foreign Communists" and immediately exiled a number of top UNO party members from the country.

Repression continued after the inauguration of President Romero, with his new government declaring a state-of-siege and suspending civil liberties. In the countryside, the agrarian elite organized and funded paramilitary death squads, such as the infamous Regalado's Armed Forces (FAR) led by Hector Regalado. While the death squads were initially autonomous from the Salvadoran military and composed of civilians (the FAR, for example, had developed out of a Boy Scout troop), they were soon taken over by El Salvador's military intelligence service, National Security Agency of El Salvador (ANSESAL), led by Major Roberto D'Aubuisson, and became a crucial part of the state's repressive apparatus, murdering thousands of union leaders, activists, students and teachers suspected of sympathizing with the left.Stanley, 2012, p. 120 The Socorro Jurídico Cristiano (Christian Legal Assistance) – a legal aid office within the archbishop's office and El Salvador's leading human rights group at the time – documented the killings of 687 civilians by government forces in 1978. In 1979 the number of documented killings increased to 1,796.Socorro Jurídico Cristiano The repression prompted many in the Catholic Church to denounce the government, which responded by repressing the clergy.Library of Congress. Country Studies. El Salvador. Background to the Insurgency.

Historian M. A. Serpas posits displacement and dispossession rates with respect to land as a major structural factor leading ultimately to civil war. El Salvador was an agrarian society, with coffee fueling its economy, where "77 percent of the arable land belonged to .01 percent of the population. Nearly 35 percent of the civilians in El Salvador were disfranchised from land ownership either through historical injustices, war or economic downturns in the commodities market. During this time frame, the country also experienced a growing population amidst major disruption in agrarian commerce and trade."

Coup d'état, repression and insurrection: 1979–1981

Military coup October 1979 With tensions mounting and the country on the verge of an insurrection, the civil-military Revolutionary Government Junta (JRG) deposed Romero in a coup on 15 October 1979. The United States feared that El Salvador, like Nicaragua and Cuba before it, could fall to communist revolution. Thus, Jimmy Carter's administration supported the new military government with vigor, hoping to promote stability in the country. While Carter provided some support to the government, the subsequent Reagan administration significantly increased U.S. spending in El Salvador. By 1984, Ronald Reagan's government would spend nearly $1 billion on economic aid for the Salvadoran government.

The JRG enacted a land reform program that restricted landholdings to a 100-hectare maximum, nationalised the banking, coffee and sugar industries, scheduled elections for February 1982, and disbanded the paramilitary private death squad Organización Democrática Nacionalista (ORDEN) on 6 November 1979.

The land reform program was received with hostility from El Salvador's military and economic elites, however, which sought to sabotage the process as soon as it began. Upon learning of the government's intent to distribute land to the peasants and organize cooperatives, wealthy Salvadoran landowners began killing their own livestock and moving valuable farming equipment across the border into Guatemala, where many Salvadoran elites owned additional land. In addition, most co-op leaders in the countryside were assassinated or "disappeared" soon after being elected and becoming visible to the authorities.NACLA, Revolution Brews cited in McClintock 1985, p. 270 The Socorro Jurídico documented a jump in documented government killings from 234 in February 1980 to 487 the following month.

Under pressure from the military, all three civilian members of the junta resigned on 3 January 1980, along with 10 of the 11 cabinet ministers. On 22 January 1980, the Salvadoran National Guard attacked a massive peaceful demonstration, killing up to 50 people and wounding hundreds more. On 6 February, US ambassador Frank Devine informed the State Department that the extreme right was arming itself and preparing for a confrontation in which it clearly expected to ally itself with the military.United States Embassy in San Salvador, cable 02296, 31 March 1980. The Washington Post, 31 March 1980.National Security Archives, El Salvador: The Making of US Policy, 1977–1984, p. 34.

Criticism of US support

"The immediate goal of the Salvadoran army and security forces—and of the United States in 1980, was to prevent a takeover by the leftist-led guerrillas and their allied political organizations. At this point in the Salvadoran conflict the latter were much more important than the former. The military resources of the rebels were extremely limited and their greatest strength, by far, lay not in force of arms but in their 'mass organizations' made up of labor unions, student and peasant organizations that could be mobilized by the thousands in El Salvador's major cities and could shut down the country through strikes."