[1] In February 1973, he opposed the appointment of retired Uruguayan General Antonio Francese to occupy the position of Minister of National Defense by President Juan María Bordaberry.

As a result, he began to ignore the orders of the political power, within the context of the institutional crisis that led to the 1973 Uruguayan coup d'état.

Upon completing his studies, he entered the Military School of the Uruguayan Army, graduating as Alférez (Ensign) of Infantry in 1940.

On September 9, 1971, Caldas was instructed by President Jorge Pacheco Areco, to conduct, along with the Uruguayan Army and Navy, anti-guerrilla operations against the Movimiento de Liberación Nacional-Tupamaros urban guerrilla.

In March 1974 he retired from the Air Force, and on November 26, 1974, he was appointed as Ambassador of Uruguay to the governments of the United States and Canada.