Over the next two years the Allies slowly captured one island base after another, trying to get closer to Japan itself, where it planned to launch massive strategic air attacks and, only if absolutely necessary, execute a ground invasion. By July 1944, the US recaptured Guam and captured Tinian, which finally put them in attacking range of mainland Japan using the new Boeing B-29 bombers. Despite the advances of the Allies, massive fighting was still taking place, both in South-East Asia with the Japanese offensive in India and in the Pacific, with the Battle of the Philippine Sea, where Japan suffered major losses and definitively lost the ability to rely on aircraft carriers. In later October, a combined attack of American and Australian forces took on the Imperial Japanese Navy during the Battle of Leyte Gulf in what was to be the largest naval battle of World War II and possibly the largest naval battle of all time. The Allied victory achieved its stated goal of further severing oil supplied to the Japanese army, which was already struggling to fuel the remainder of its naval power. The battle of Leyte Gulf is also notable as the first battle in which Japanese aircraft carried out organized "kamikaze" attacks.