[3] He was involved in the anti-Fascist movement in Italy before World War II.
Imprisoned from 1931 to 1932 as a result of his political activities, Salvadori fled Italy for Switzerland.
In 1943 he joined the British army and after participating in landings at Salerno and Anzio, parachuted into Italy to organize resistance.
As agent of the British Special Operations Executive, Salvadori played a central role in providing weapons supplies for partisan formations and in pushing the Action Party to cooperate with the Italian Monarchy after the "svolta di Salerno" (1944).
He served on the faculty of Smith College from 1945 until his retirement in 1973, with two notable breaks: in 1948-49 he was director of the Division of Political Science of UNESCO in France and in 1952 he worked as a political analyst for the Information Service of the Secretariat of NATO.