A member of the peronist Justicialist Party, he also briefly served as Minister of Defense during the presidency of Isabel Perón in 1976 and as Argentina's ambassador to the Holy See from 1974 to 1976.

[1] Although not an early supporter of the Peronist movement, Guardo decided to become involved in politics after meeting General Juan Perón in person in 1945.

As president, Guardo had all of Perón's speeches and public interventions compiled into a single book and printed at the Congress press, which he later gifted to the General.

[3] Following the 1955 coup d'état that overthrew Perón and established a military dictatorship, Guardo and his family went into exile, finding refuge at the Argentine embassy in Haiti.

[1] He was married to Lilian Lagomarsino, an heiress and protocol instructor who was Eva Perón's escort and confidant during her 1947 European tour.