After 1960, Somoza's restrictions on political opposition combined with the success of revolutionary movements in Cuba and elsewhere emboldened a group of activists to challenge his hold on power. Led by Carlos Fonseca, Tomás Borge, and Silvio Mayorga, the Frente Sandinista de Liberación Nacional (FSLN, Sandinista National Liberation Front) began its operations in Nicaragua's largest cities. The Sandinistas took their name from Augusto César Sandino (1895–1934), who led a nationalist rebellion against the U.S. military occupation of Nicaragua in the 1920s and early 1930s until his assassination by the U.S.-created Guardia Nacional (National Guard) enabled Somoza to seize control.
Designed as an urban guerrilla force, the FSLN had little impact. The corruption of the Somoza regime, however, helped sustain its organizational efforts. Shifting from urban to rural districts, the organization survived military defeats and factionalism well into the 1970s. In 1975, the group split into three organizational lines. The Prolonged Popular War faction (GPP), under the direction of Fonseca, Borge, and Henry Ruíz, led the effort to mobilize the population for war against the dictatorship. A second faction, led by Luis Carrión, Jaime Wheelock, and Carlos Núñez, focused on organizing workers and the urban underclass. A third group that would form the core of the Sandinistas' political force after 1979 built connections with business groups and other political opposition forces.
Somoza steadily lost popular support during the 1970s, and his reactionary policies helped the Sandinistas build their base and expand military operations. In 1974 the FSLN sponsored the formation of the United People's Movement (MPU), which linked unions, university students, and church-affiliated groups with their struggle. After 1977, the Sandinistas coordinated their campaigns with allied groups. Attacks against symbols of the Somoza regime, highlighted by the occupation of the National Palace and an ensuing prisoner exchange in 1978, demonstrated the FSLN's capabilities while it continued to build popular support.
International pressure and dwindling support from President Jimmy Carter's administration led Somoza to choose exile before defeat, and on 19 July 1979 the Sandinistas occupied Managua and took command of the government. The splits in the movement did not initially affect the Sandinistas' efforts. After declaring the unification of the movement's factions in 1979, the FSLN outlined its plans for the political, social, and economic transformation of Nicaragua. Nationalism, agrarian reform, progressive social reforms, universal medical care, and popular education clearly showcased the government's socialist orientation.
The Carter administration briefly offered humanitarian assistance to the Sandinistas, but domestic political pressure from conservatives forced the administration to end aid in 1980. The staunchly anticommunist President Ronald Reagan treated the Sandinistas much more harshly. In 1981 the Reagan administration engineered the end of financial support from international lending agencies and authorized the Central Intelligence Agency (CIA) to coordinate a counter-revolutionary movement in Nicaragua.
In 1982, with nearly $20 million from the United States, the Contra rebels began military operations against the Sandinista government. Launching small-scale raids from Honduras and Costa Rica, the Contras created an ongoing military challenge that sapped Sandinista resources. Nevertheless, the Sandinistas organized a government structure that allowed them to dominate the political process. A national directorate controlled the political process, the FSLN created youth groups and neighborhood committees to expand its base, and corporate bodies coordinated the political life of students, workers, and professionals.
Internationally, the Sandinistas counted on immediate support from Cuba and the Soviet Union. The Sandinista leadership chose to affiliate with the Socialist International rather than the Moscow-dominated Comintern. Harassed by Contra incursions and placed under a U.S. trade embargo that affected economic relations with its neighbors, the Sandinistas came to rely more and more upon economic and military aid from their communist allies.
Increasingly isolated, the Nicaraguan economy performed poorly under the Sandinistas. Inflation, shortages, and meager productivity hindered the government's efforts to diversify and expand the economy. Ultimately, the flagging economy undermined the Sandinistas' many ambitious social projects. Defense programs interfered with the agrarian reform program and exacerbated prickly government relations with the Miskito Indians in eastern Nicaragua.
In 1984, the U.S. Congress passed the Boland Amendment, which forbade further Contra funding. The Reagan administration skirted the restriction by illegally selling weapons to Iran as a way of generating funds for Contra operations. While revelations of these extralegal maneuvers rocked the Reagan administration, the Contra war continued.
To bring legitimacy to their regime, the Sandinistas organized national elections in 1984. Splits in the opposition forces allowed the Sandinistas to use their organizational strength to great effect. Daniel Ortega won election as president, and the Sandinistas worked to preserve their revolution's achievements, seeking international assistance in their ongoing conflict with the United States. In 1984, the International Court of Justice ruled that American actions in Nicaragua violated international laws but had no effect on U.S. policy. Latin American efforts to negotiate a peace settlement bore no fruit until 1989. Led by Costa Rican President Oscar Arias Sánchez, the 1989 Central American Peace Initiative brought about a final settlement. Under the plan, the Contras would disarm and the Sandinistas would authorize a national election, scheduled for February 1990.
Opposition forces united behind candidate Violeta Barrios de Chamorro, the widow of a leading opponent of the Somoza dictatorship who had been assassinated in 1978. Poor economic conditions and factionalism among the Sandinistas allowed the United Nicaraguan Opposition movement to capture the presidency and a majority of the seats in the National Congress. The Sandinistas' 1990 electoral defeat left the movement weakened and divided. Out of power, Sandinista leaders have recast their movement as a political party that competes effectively in local and national elections.
Gilbert, Dennis. Sandinistas: The Party and the Revolution. New York: Blackwell, 1988.