This strategy was possible in part because the Allies used submarine and air attacks to blockade and isolate Japanese bases, weakening their garrisons and reducing the Japanese ability to resupply and reinforce them. Thus troops on islands which had been bypassed, such as the major base at Rabaul, were useless to the Japanese war effort and left to "wither on the vine". General Douglas MacArthur greatly supported this strategy in his effort to regain the Philippines from Japanese occupation. This strategy began to be implemented in late 1943 in Operation Cartwheel. While MacArthur claimed to have invented the strategy, it initially came out of the Navy. While this strategy pre-dated World War II by many decades, MacArthur was the first Allied theater commander to practice this during the Allied offensive in the Pacific Theater. MacArthur's Operation Cartwheel, Operation Reckless and Operation Persecution were the first successful Allied practices of leapfrogging in terms of landing on lightly guarded beaches and very low casualties but cutting off Japanese troops hundreds of miles away from their supply routes. MacArthur said his version of leapfrogging was different from what he called island hopping, which was the style favored by the Central Pacific Area commanded by Admiral Chester Nimitz that favored direct assaults on heavily defended beaches and islands leading to massive casualties for such small parcels of land like at Tarawa, Peleliu, Saipan, Guam, Iwo Jima, and Okinawa. MacArthur worked together with Admiral William Halsey, commander of the South Pacific Area but subordinate to MacArthur in Operation Cartwheel, in perfecting leapfrogging.