Several Japanese naval officers had been impressed by the British action in the Battle of Taranto, in which 21 obsolete Fairey Swordfish disabled half the "Regia Marina" (Italian Navy). Admiral Yamamoto even dispatched a delegation to Italy, which concluded a larger and better-supported version of Cunningham's strike could force the U.S. Pacific Fleet to retreat to bases in California, thus giving Japan the time necessary to establish a "barrier" defense to protect Japanese control of the Dutch East Indies. The delegation returned to Japan with information about the shallow-running torpedoes Cunningham's engineers had devised.