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Sandinista National Liberation Front (FSLN)

Insurgency Overview

The Sandinista National Liberation Front, or Frente Sandinista de Liberación Nacional (FSLN) is a left-wing political party in Nicaragua. Named after Augusta César Sandino, an anti-imperialism Nicaraguan fighter from the 1920s, the group has grown from an armed resistance at its foundation in 1961 into the country's dominant political party (Bodenheimer, 2019).

The group was established as an opposition force to the dictatorship of the Somoza family, spending more than a decade organizing political support — primarily from students, workers, and peasants — and launching attacks against Nicaraguan forces. In the mid-1970s the retaliation from the Somoza family left two of the FSLN founders dead and split the group into three factions with somewhat differing approaches to resistance. The groups then reunited under Daniel and Humberto Ortega during the Nicaraguan revolution of 1978-79 which ended in the toppling of the Somoza dictatorship (Britannica, 2023).

The Sandinistas then governed Nicaragua until 1990, during which period they faced armed resistance from the CIA-backed Contras. In 1990, the Sandinistas lost elections to a coalition funded by the United States, which was headed by Violeta Chamorro. Chamorro was the daughter of a wealthy Nicaraguan cattle rancher who received much of her early education in the United States. She returned to Nicaragua after the death of her father in 1950, where she married the editor of the newspaper La Prensa. After getting more involved with the newspaper and Nicaraguan politics, being exiled to Costa Rica and returning, Violetta became a member of the Sandinista ruling junta in 1979-80. However, she soon became disillusioned with the party and split away before getting involved with the National Opposition Union (UNO). Chamorro and the UNO received funding from the US, as part of the CIA’s campaign to destabilize the FSLN regime (Kansas).

Since then, Daniel Ortega, who remains the current leader of the FSLN, has been reelected in 2006, 2011, and 2016 (Bodenheimer, 2019). Since his 2016 reelection, Ortega has demonstrated increased corruption and authoritarianism — such as violent protest repression, the jailing of opposition leaders, and the shuttering of numerous NGOs and media outlets (POLITICO, 2022). Along with the increased accusations of corruption, Ortega's popularity has waned significantly. As of polling in June 2023, popular support for the FSLN and Ortega is only 15% and even within that percentage, party members are divided about Ortega himself. About 35% of the Sandinista supporters disapprove of Ortega and his government, illustrating the internal ruptures within the party (Dialogue, 2023).

History and Foundations

The FSLN was founded in 1961 by Tomás Borge, Carlos Fonseca, and Silvio Mayorga, with Fonseca usually being seen as the soul of the organization, as well as the mastermind behind the ideology of the group. Fonseca was inspired by the success of the Cuban revolution and by resistance leaders such as Che Guevara and Augusta César Sandino (Bodenheimer, 2019).

Sandino, whom the FSLN was named after, was a guerrilla resistance fighter against the US occupation of Nicaragua in 1926. He then led a group of several hundred resistance fighters against the Nicaraguan National Guard and US Marines in opposition to the US occupation. After the end of the occupation in 1933, Sandino was invited to meet with the Somoza authorities in order to attempt to reach a peace agreement, where he was instead abducted and executed on Somoza’s orders (Britannica, 2024).

At the time of the FSLN’s founding, Fonseca, Mayorga, and Borge were living in exile in Honduras as previous members of the Nicaraguan Socialist Party. The ideological transition that led to the founding of FSLN began after the success of the Cuban revolution. Fonseca had traveled to Havana just months after the revolution and he, as well as other leftist students, were inspired to attempt to bring a similar revolution to Nicaragua (Bodenheimer, 2019).

Objectives and Ideology

The initial goals of the FSLN upon its founding were 1: to achieve Nicaraguan liberation and sovereignty — highlighted by the realities of U.S imperialism and 2: to create a socialist state which the founders believed would serve to end the exploitation of the Nicaraguan workers and lower classes (Bodenheimer, 2019).

Initially, the FSLN followed Guevara’s “foco theory” of guerilla warfare, which emphasized the use of mobility, surprise, and covering terrain in order to make up for the resistance's lack of arms and numbers. The goals of this type of combat were generally to disrupt the regime's communication, transport, and supply networks. At the outset, the group aimed to stir up support primarily among peasants, students, and workers. For several years, they struggled to garner the types of grassroots support they hoped to find, which eventually led to a change in tactics. In January of 1965, Carlos Fonseca was deported to Guatemala, where he was introduced to the concept of “protracted people's war” by Luís Turcios Lima — a member of the Rebel Armed Forces (FAR), an offshoot of the Guatemalan Communist Party. The idea of “protracted people's war” came from Asian guerrilla theorists Mao Zedong and Vo Nguyen Giap.

The following year, a contingent of the FSLN led by Oscar Turcios fought in Guatemala with the Rebel Armed Forces on the Zacapa Front. Following these events, the FSLN had gained a great deal of practical experience and the seeds of a new ideological framework. Back in Nicaragua, the Sandinistas were primarily concerned with organizing a viable support network through the peasant classes. However, in May of 1967, their activities were discovered by the regime, and a counter-strike was launched which led to the destruction of one-third of the organization's forces — a column that had been led by Silvio Mayorga (Nolan, 1986).

Military & Political Capabilities

Over the years following the 1967 counter-strike, the FSLN went through a significant organizational and ideological shift. The group shifted to a more distributed leadership structure, with power being decentralized among the seven members of their National Directorate. While this divide also sewed the seeds of internal division that would come to fruition later, it also served to foster resilience within the movement. The group adopted the “Prolonged Popular War” or Guerra Popular Prolongada (GPP) as a strategic doctrine. The GPP was loosely based on the Vietnamese and Chinese revolutions and called for the “accumulation of forces in silence. The group’s military activity dropped off and their focus turned toward recruitment and guerrilla training, where groups were sent to the north central mountain zone in order to build a support base in preparation for renewed military engagements.

From 1970 through 1974 the organization stuck to its ideals and did not engage in guerrilla warfare, but rather focused on building a rural peasant network. In this period the urban side of the FSLN worked with other groups, such as the Revolutionary Student Front (FER) and the Christian Revolutionary Movement (MCR), in order to free Sandinista prisoners, spread propaganda, and gather supplies for the guerrillas. This period of silent accumulation ended on December 27, 1974, when the home of a powerful Somoza supporter was seized in Managua. Following this event, President Anastasio Somoza accepted the FSLN’s demands but retaliated with a campaign of violence and destruction perpetrated by the Nicaraguan National Guard.

For a while, the guerrilla fighters and the national guard traded blows but eventually, the superior weaponry and manpower of Nicaraguan forces won out, forcing the main guerrilla force to flee into the remote jungles of eastern Nicaragua. During this period four major commanders of the FSLN, including Carlos Fonseca and Silvio Mayorga, were killed and Tomás Borge was captured (Nolan, 1986).

Approach to Resistance

After the seeming defeat of the guerrilla fighters and the death of Fonseca in 1976, the FSLN split into three different factions, or tendencias, that disagreed over whether the group should again attempt to accumulate forces and support in silence, or ally with other political groups amidst the growing rebellion. The groups remained estranged until 1978 when the factions united again under the Terceristas, the third faction that was headed by Daniel and Humberto Ortega. This reunification of the different factions left the FSLN united, with around 5,000 fighters. The FSLN called for a national uprising in September of that year, which catalyzed the Nicaraguan Revolution. By the spring of 1979, the revolution was in full swing, with the FSLN maintaining various rural strongholds while most cities were facing significant uprisings. By late June, the FSLN was engaged in combat for Managua, and on July 19th, they took control of the capital city. The National Guard and previous governmental strongholds collapsed, with many of the former members fleeing the country to Guatemala, Honduras, or Costa Rica (Bodenheimer, 2019).

Once the FSLN gained power, they set up a National Directorate, which comprised three members from each of the factions, to lead the country. Their efforts to unify and rebuild the country were complicated by the election of Ronald Reagan in 1980 and the ensuing US involvement in Nicaragua.

International Relations and Partnerships

In 1981, Reagan and the CIA began to fund exiled paramilitary forces in Honduras in an attempt to destabilize the FSLN’s new regime. This was the beginning of the Contras (counter-revolutionaries) engagement with the FSLN (Bodenheimer, 2019).

In response to this, the FSLN established a Sandinista Popular Army of 50,000 men headed by Humberto Ortega and a secret police force to guard against espionage that was led by Tomás Borge. At the same time, the FSLN was experiencing internal conflict due to ideological differences which would lead to the resignations of many non-Marxist members of the leadership, primarily instigated by issues of political rights. The internal disintegrations combined with the pressure from the Contra’s resistance pushed the FSLN farther and farther to the left until they became dependent on the support of the Soviet Union and Cuba (Britannica, 2023).

By 1984 and with US support, the Contras numbered 15,000 and were engaging in significant sabotage acts against Nicaragua. However, that same year, the US Congress passed a law that banned future funding to the Contras. The CIA remained undeterred and instead began to fund the Contras through the illegal sale of arms to Iran. This later became known as the Iran-Contra affair. The internal difficulties of the FSLN, embargos from countries like Venezuela and Mexico, and the entanglement with the Contra’s and US aggression pushed the government toward a more authoritarian approach to maintaining order (Bodenheimer, 2019).

In 1990, under strong international pressure, Nicaragua held free elections and the FSLN lost to a U.S. assembled coalition led by Violeta Chamorro — the then-presidential candidate for the 14-party National Opposition Union (Unión Nacional Opositor) (Britannica, 2023).

Following these elections, the Sandinistas had once again become an opposition party, and many members were left disillusioned with the reality of the party’s government and leadership. In the wake of their loss, Daniel Ortega was the rallying point for the FSLN and his consolidation of power led him to run for president again in 1996, 2001, and 2006. Ortega was successfully re-elected in 2006, though not before being found guilty of embezzlement in 2003 and sentenced to 20 years in jail (this sentence was overturned in 2009). Along with Ortega's sentence being overturned in 2009, the Supreme Court also lifted constitutional limits on presidential terms which allowed Ortega to be re-elected in 2011. Further barriers were lifted after this allowing for a following reelection in 2016. Ortega’s position has strayed further and further into authoritarianism as time has progressed, with significant repression of student protests, reports of media harassment, the jailing of political opponents, and accounts of torture and illegal detentions. As of September 2018, Ortega's government has outlawed protest in the country (Bodenheimer, 2019).

Following these events, in January of 2019, the FSLN was expelled from the Socialist International — an international organization of political parties seeking to establish socialist democracies — for violations of human rights and democratic values. The foreign minister of Spain, Joseph Borrell Fontelles, stated on twitter that “socialism is incompatible with tyranny, in regards to the expulsion of the FSLN (Havana, 2019).

As of 2023, Nicaragua scored only 19/100 in the Freedom House Scale that ranks how free different countries are. Nicaragua has 5 out of 40 possible political rights and 14 out of 60 possible civil liberties, according to Freedom House. Between February and May of 2023, at least 50 outspoken critics of the current government — including political rivals — received prison sentences in trials that have been denounced as unfair (Freedom, 2023).

Recent polling has illustrated a significant decline in popularity of Ortega and the FSLN. As of June 2023, support for the FSLN and Ortega among the population was 15%. Even within Sandinista supporters, only 65% supported Ortega and the current government (Dialogue, 2023).

Works Cited (MLA-Style)

Bodenheimer, Rebecca. “History of the Sandinistas in Nicaragua.” ThoughtCo, ThoughtCo, 20 Dec. 2019,

Britannica. “César Augusto Sandino.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 1 Jan. 2024,

Britannica. “Sandinista.” Encyclopædia Britannica, Encyclopædia Britannica, inc., 21 Apr. 2023,

Britannica. “Violeta Barrios de Chamorro.” Encyclopædia Britannica, Inc., Britannica, 14 Oct. 2023,

“The Drop in Popularity and Support for Daniel Ortega among the FSLN.” The Dialogue, The Dialogue, 19 July 2023,

“Nicaragua: Freedom in the World 2023 Country Report.” Freedom House, Freedom House, 2023,

Nolan, David. “From FOCO to Insurrection: Sandinista Strategies of Revolution.” Web Archive, Accessed 19 Jan. 2024

“Ortega’s FSLN Expelled from the Socialist International.” Havana Times, Havana Times, 30 Jan. 2019,

“Sandinistas Complete Their Political Domination of Nicaragua.” POLITICO, POLITICO, 11 Aug. 2022,

“Violeta Chamorro.” Kansas State University, Kansas State University, Accessed 23 Jan. 2024.

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