The earlier British raid on Taranto, which is often regarded as the inspiration for the Pearl Harbor attack, achieved its strategic goal being a considerably smaller operation that inflicted much less devastation. Not only did it cost the Italian fleet half of its capital ships in one night, furthermore in response the "Regia Marina" immediately transferred its undamaged ships from Taranto to Naples to protect them from similar attacks, until the defences at Taranto (mainly the anti-torpedo nets) were brought up to adequate levels to protect them from further attacks of the same kind (which happened between March and May 1941). After Taranto the balance of power swung to the British Mediterranean Fleet which now enjoyed more operational freedom: when previously forced to operate as one unit to match Italian capital ships, they could now split into two battlegroups; each built around one aircraft carrier and two battleships. Battleships were found to be more useful in the confines of the Mediterranean as opposed to the expanses of the Pacific; furthermore the older US battleships were too slow to escort the carriers and were chiefly used as fire support for amphibious operations. Although the US Pacific fleet had five out of eight battleships sunk (three of them permanent losses) at Pearl Harbor, this instead meant a reliance upon the untouched aircraft carriers for offensive operations against the Japanese.