After the fall of Ubico, a reform period was initiated with the adoption of a democratic constitution and the election of Juan José Arévalo (* 1905, † 1990; 1945–51) as President, which Jacobo Arbenz Guzmán (* 1913, † 1971; 1951–54) continued (Expropriation of large domestic and foreign landowners, which particularly affected the UFCO; increase in the minimum wage).
In 1954 the USA, which saw the interests of the UFCO threatened, supported the coup of Carlos Castillo Armas (* 1914, † 1957), who as president (1954–57) banned parties and unions and restored the old ownership. After the military had become the main bearers of political power, they occupied a large part of the cabinet, governor and high administrative posts. The presidential constitution of 1965 enabled the transition to a civil government under Julio César Méndez Montenegro (* 1916, † 1996; 1966-70), but it was followed by elections (with partially falsified results) by the military Carlos Araña Osorio (1970-74), Kjell Laugerud García (1974-78) and Romero Lucas García (1978-82).
Especially in the traditional settlement areas of the indigenous population in the northern departments, since the mid-1960s there have been civil war-like clashes between the army and paramilitary groups on the one hand and the various left-wing guerrilla movements on the other. The militant clashes and state repression increasingly affected the civilian population as well. Above all under the junta of Efraín Ríos Montt (* 1926, † 2018; 1982/83), which among other things suspended the constitution, dissolved parties and repeatedly bloodily suppressed unrest, violence and terror were a central means of maintaining the fragile political order. In 1983, his defense minister launched a coup Oscar Humberto Mejía Victores (* 1930, † 2016), whose system of government provoked a new escalation of violence.
In November 1985, according to Allcitycodes, the Partido Democracia Cristiana Guatemalteca (PDCG) received a majority in local, parliamentary and presidential elections. The office of president was taken over by civilian Marco Vinicio Cerezo Arévalo (* 1942) in January 1986. Shortly before, the military government had announced a general amnesty; the army also played a key role under civil government (coup attempts in 1988 and 1989). In August 1988 there were initial contacts between the government and the guerrilla umbrella organization (Unidad Revolucionaria Nacional Guatemalteca, URNG), but negotiations were repeatedly interrupted (among other things because the URNG refused to lay down its arms).
After the conservative Jorge Serrano Elias (* 1945) won the presidential elections in January 1991, the peace talks were resumed, now under the supervision of the UN. Nonetheless, domestic political tensions grew, mainly due to the acts of violence committed by death squads against the majority of the indigenous population.
The award of the Nobel Peace Prize to the Indian Rigoberta Menchú Tum in 1992 drew the international public’s attention to the country’s problems. Against this background, the President partially suspended the constitution on May 25, 1993, dissolved the parliament and the highest judicial authorities and ordered the convening of a constituent assembly. This coup, initially supported by the military, failed due to broad social resistance. After Serrano Elias was deposed under pressure from the military on June 1st. and violent protests against the army-supported successor, the parliament elected on June 5th. the previous human rights commissioner Ramiro de León Carpio (* 1942) to the president. His campaign against corruption in state institutions led to a conflict with Parliament and the Supreme Court, which was settled through a constitutional reform (approved by referendum on January 30, 1994). The right-wing parties won the early elections for an interim parliament in August 1994, which became necessary as a result. Despite setbacks, there were talks and agreements between the government and URNG in 1994/95. The guerrilla organization first called on its supporters to take part in the parliamentary and presidential elections in November 1995. The ballot on 07.01.1996 won Alvaro Enrique Arzú Irigoyen (* 1946, † 2018; PAN). After the announcement of an indefinite ceasefire between URNG and the army in March 1996, a peace agreement was signed in December 1996 that ended the decades-long civil war.
In 1994 the government and the URNG agreed to set up an international truth commission to investigate human rights violations since the 1960s. In this context, the negotiating parties agreed that the results of the Commission should not have any criminal consequences. The Commission presented its final report in 1999. According to the report, the state security forces (military, police, Patrullas de Autodefensa Civil [PAC] and secret service), but also the guerrilla movement (which accounts for 3% of all murders) murdered around 200,000 people between 1962 and 1996. The one under Ríos Montt The “scorched earth policy” practiced, in which entire villages were burned to the ground in order to deprive the guerrillas of support and supplies, was classified as genocide in the final report. However, it was not until 2009 that the Guatemalan judiciary found a military guilty of serious human rights violations for the first time.