This was an Italian unrealised naval plan to intercept and destroy a British naval force in the Mediterranean (summer 1941).
When Italy entered World War II on the Axis side on 10 June 1940, the Italian navy was faced with the immediate need to concentrate forces for the protection of the shipping required to reinforce and supply the Italian forces in Libya. This essentially defensive effort was the priority for the rest of 1940 and the first months of 1941, and was generally successful.
So it was not until the early summer of 1941 that planning began for the Italian navy’s first offensive operation, which received the codename 'BA' (ii) and was designed to allow Italian light forces to surprise British naval units engaged in the surveillance of coastal traffic between the Balearic islands and Cartagena in neutral but Axis-inclined Spain.
In the aftermath of Germany’s 'Barbarossa' invasion of the USSR in June 1941, British destroyers based at Malta had intensified their patrols in the western part of the Mediterranean Sea off Spain in their search for contraband cargo (any goods destined for Germany and Italy) on board Spanish, Vichy French, Swiss and Turkish ships. A study of British operational methods, and of the British practice of operating with only two groups of destroyers without the support of cruisers, persuaded the planning staff of the Supermarina to develop a plan to engage and destroy such a force. To overcome the limited range of their destroyers, the Supermarina decided to concentrate the attack force in La Maddalena on the island of Sardinia to the west of the Italian mainland.
The Italian force was to have been built round two 'da Giussano' class light cruisers and four destroyers, which were to leave port at 11.00 on the day before the anticipated engagement and, taking advantage of limited extent of British aerial reconnaissance in the area, reach the designated area between Cartagena and the Balearic islands during the morning of the following day: in 44 hours the attack force was therefore to have covered some 910 miles (1465 km) at about 18 kt, which would provide the force’s commander with a full-speed endurance of only about one hour for the engagement.
It was also clear to the Italians that they would need additional intelligence about the British patrol schedule to minimise the amount of fuel that would have to be burned in locating the British force, and air reconnaissance was therefore to be intensified during the period immediately before, during and after the operation.
Meanwhile, from June 1941 the British introduced a form of naval undertaking new to the Mediterranean theatre, namely the passage of naval groups, composed of two aircraft carriers with an escort including a battleship, to deliver warplanes to Malta. At this point the Italians decided to abandon their 'BA' concept for two basic reasons: firstly it was not possible to ascertain when the British destroyers would be engaged in a patrol, and secondly there was an increasing demand for light cruisers to escort convoys to Libya. A later study decided that it would have been better to make use of more modern cruisers as these were more protected than the faster, but more vulnerable, 'di Giussano' class cruisers.