In a July 1983 speech marking the 30th anniversary of the Cuban Revolution, Castro condemned Reagan's administration as a "reactionary, extremist clique" who were waging an "openly warmongering and fascist foreign policy". Castro feared a US invasion of Nicaragua and sent Ochoa to train the governing Sandinistas in guerrilla warfare, but received little support from the USSR. In 1985, Mikhail Gorbachev became Secretary-General of the Soviet Communist Party; a reformer, he implemented measures to increase freedom of the press (glasnost) and economic decentralization (perestroika) in an attempt to strengthen socialism. Like many orthodox Marxist critics, Castro feared that the reforms would weaken the socialist state and allow capitalist elements to regain control. Gorbachev conceded to US demands to reduce support for Cuba, with Soviet-Cuban relations deteriorating. On medical advice given him in October 1985, Castro gave up regularly smoking Cuban cigars, helping to set an example for the rest of the populace. Castro became passionate in his denunciation of the Third World debt problem, arguing that the Third World would never escape the debt that First World banks and governments imposed upon it. In 1985, Havana hosted five international conferences on the world debt problem. By November 1987, Castro began spending more time on the Angolan Civil War, in which the Marxist MPLA government had fallen into retreat. Angolan President José Eduardo dos Santos successfully appealed for more Cuban troops, with Castro later admitting that he devoted more time to Angola than to the domestic situation, believing that a victory would lead to the collapse of apartheid. In response to the siege of Cuito Cuanavale in 1987–1988 by South African-UNITA forces, Castro sent an additional 12,000 Cuban Army troops to Angola in late 1987. From afar in Havana, Castro was closely involved in the decision-making about the defence of Cuito Cuanavle and came into conflict with Ochoa, whom he criticized for almost losing Cuito Cuanavle to a South African-UNITA assault on 13 January 1988 despite warning for almost two months prior that such an attack was coming. On 30 January 1988, Ochoa was summoned to a meeting with Castro in Havana where he was told that Cuito Cuanavale must not fall and to execute Castro's plans for a pull-back to more defensible positions over the objections of the Angolans. The Cuban troops played a decisive role in the relief of Cuito Cuanavale, breaking the siege in March 1988, which led