In 1989, Arns sent a letter to Fidel Castro on the 30th anniversary of the Cuban Revolution. He praised Cuba's record on social justice and wrote that "Christian faith discovers in the achievements of the revolution signs of the kingdom of God... You are present daily in my prayers, and I ask the Father that he always concede you the grace of guiding the destinies of your country." Political and theological conservatives, including Cardinal Eugenio Sales of Rio de Janeiro, protested what they interpreted as support for Castro's continued rule. Leonardo Boff, the foremost figure in the liberation theology movement, defended Arns, saying: "Cuba carried out a revolution against hunger by ending prostitution, illiteracy and misery. Dom Paulo is not a socialist, but a man of the poor and the oppressed." Arns said the letter was part of an ongoing dialogue with Castro and that he opposed dictatorship.