Suárez was removed from his post at YPF by the 1966 military coup against Illia. He developed a good working relationship with the banned Peronist movement, and had become a close adviser to party leader Ricardo Balbín when the dictatorship called for general elections in 1973. Balbín chose his running-mate, Fernando de la Rúa, on his advice. The UCR ticket was defeated in the 1973 elections, and Suárez did not return to active politics until a decade later, when a subsequent dictatorship called new elections. The winner of the 1983 elections, Raúl Alfonsín, had challenged Suárez's mentor, Balbín, for the leadership of the UCR in 1972. He nevertheless appointed Suárez director of Segba, the state electric utility company then serving Greater Buenos Aires. He served a stint as Ambassador to Mexico, from 1985 to 1986, and was named director of Argentine Intelligence Service.[1]
Suárez proposed making the SIDE expense account, long a source of controversy in Argentina due to its classified nature, a matter of Congressional purview.[2] Though the proposal was not enacted by Congress, Suárez made the agency's budget public, and during his 1986–89 tenure, this amount doubled.[3] His tenure coincided with a number of scandals, however, including the filming of the UCR's 1989 presidential campaign television ads on a SIDE base, with employees in the background, the involvement of numerous SIDE officials in the far-right Carapintadas, and the surveillance of opposition senators for human weaknesses to be used against them in future political operations.[3]