In the South West Pacific, a conventional strategic bombing campaign was out of the question, as industrial targets in Japan were well beyond the range of even the largest strategic bombers operating from bases in Australia and New Guinea. Therefore, the primary mission of the Allied bomber force was interdiction of Japanese supply lines, especially the sea lanes. The results of the effort against the Japanese convoy in January were very disappointing; some 416 sorties had been flown with only two ships sunk and three damaged, so clearly, a change of tactics was in order. Group Captain Bill Garing, an RAAF officer on Kenney's staff with considerable experience in air-sea operations, including a tour of duty in Europe, recommended that Japanese convoys be subjected to simultaneous attack from different altitudes and directions.