of the opposition of Acción Democrática. Caldera also reformed the 1961 Constitution to remove a ban on election to public office for people who had been sentenced to more than three years in prison, which had been specifically designed to politically disqualify General Marcos Pérez Jiménez by means of its retroactive application. Caldera closed the Industrial Technical School permanently and the Central University of Venezuela for two years due to student protests against his government. On December 9, 1970, Rafael Caldera created the Great Marshal of Ayacucho Institute of National Higher Defence Studies (IAEDEN) to further the development of a state security perspective and to contribute to the defense culture of the nation. Caldera, who raised the tax on the rent to the oil companies to 60 percent, initiated the construction of El Tablazo petrochemical complex in Zulia. Led by finance minister Luis Enrique Oberto, Caldera's government began the process of nationalizing Venezuela's oil industry. He also inaugurated the Poliedro de Caracas and the Miguel Pérez Carreño Hospital in Caracas and concluded the demarcation of borders with Brazil. Rafael Caldera ended his first term as president on March 12, 1974, and was replaced by Carlos Andrés Pérez, from Acción Democrática, who won the 1973 elections. Pacification of Venezuela In 1969, the new government inherited a country with active urban and rural guerrilla movements, bans on two important political parties, and many political leaders imprisoned. From the beginning of Caldera's presidency, this practice was suspended and constitutional guarantees thereafter were maintained. The government arrived with an attitude of ideological pluralism and dialogue across the political spectrum, entered into talks with the armed groups, legalized leftist parties, and released jailed politicians, demanding only that they stay within Venezuelan law. As a result of this effort, by the end of Caldera's presidency, for the first time in many years, no significant political organization in Venezuela planned to take control of the government by violent means. At the 1973 elections, leaders of the old guerrilla movements were elected as senators and deputies. Cabinet References See also History of Venezuela, 1958 - 1998 Rafael Caldera Second Presidency of Rafael Caldera Presidents of Venezuela History of Venezuela Rafael Caldera Caldera, Rafael