Italy has played an unexpected and oddly crucial role at key moments in Turkish diplomatic history...
In 1919, Italy's push to expand its territorial claims in Anatolia led Britain to back a Greek landing in Izmir, triggering the Turkish War of Independence.
In the 1930s, Italy's growing power in the Eastern Mediterranean created the alignment of interests between Britain and Russia that made Turkish control of the Bosporus through the Montreux Convention possible
And in 1949, Italy's inclusion in NATO definitively stripped the alliance of its North Atlantic geographic character, creating the conditions for Turkish (and Greek) membership several years later
Also if I'm remembering correctly Italian doctors supposedly saved Adnan Menderes when he had a deadly bout of malaria after WWI.