He continued his naval career after the war ended, serving between 1972 and 1973 as ship's captain on the battle cruiser Vittorio Veneto, at which time the vessel was the flagship of the Italian navy.
Stationed in the Bosphorus area to monitor movements of the Soviet merchant fleet to and from the Mediterranean, he was involved in providing the Americans with photographs of missile parts being transported to Cuba.
In the hands of the Americans these images played an important part in demolishing General Secretary Kruschev's assertions of the Soviet Union's "innocence" during the Cuban Missile Crisis.
Martini was an experienced intelligence officer untainted by the affair and took charge of the SISMI, purging the organisation of residual fascist elements and others involved in the P2 conspiracies.
His scope for manoeuvre was limited by the need to sustain existing structures in response to the country's Cold War obligations, but he nevertheless succeeded in transforming the SISMI into an efficient and modern intelligence service, and lifting from it the shadow of a "secret police" guiding spirit.