Montreux Convention Regarding the Regime of the Straits of who should control the strategically vital link between the Black Sea and Mediterranean Sea. In 1923 the Treaty of Lausanne had demilitarised the Dardanelles and opened the Straits to unrestricted civilian and military traffic, under the supervision of the International Straits Commission of the League of Nations. By the late 1930s, the strategic situation in the Mediterranean had altered with the rise of Fascist Italy, which controlled the Greek-inhabited Dodecanese islands off the west coast of Turkey and had constructed fortifications on Rhodes, Leros and Kos. The Turks feared that Italy would seek to exploit access to the Straits
Dodecanese campaign when Italian forces recaptured the island of Kastellorizo from British commandos. After the Battle of Greece in April 1941 and the Allied defeat in the Battle of Crete in May 1941, Greece and its many islands were occupied by the Axis powers. With the defeat of Axis forces in the North African campaign in spring 1943, Winston Churchill, the British Prime Minister, who at least as far back as the Gallipoli campaign in World War I had a deep interest in the region, turned his sights on the islands. The British envisaged an operation to capture the Dodecanese and Crete,