Miró was a lawyer and professor at the University of Havana and had become a noted leader in the civil opposition to President Fulgencio Batista.

It was decided that Miró would become the provisional President of Cuba depending upon the success of the invasion, and after the exiles had gained "a piece of Cuban soil".

[citation needed] As the deadline for the proposed invasion neared, Miró became increasingly frustrated with the CIA and the lack of communication between different factions.

Miró was convinced that U.S. forces would support the Cuban exile invasion, even telling other groups that 10,000 U.S. troops were on hand to assist.

In the name of God we assure you all that after the victory we will have peace, human solidarity, general well-being and absolute respect for the dignity of all Cubans without exception.