The spring of 1945 found the Allies' fortunes very much on the rise. In Europe, the Allied armies were now closing in on the Reich with the offensive against the Rhineland and crossing of the Rhine in the West, the isolation of East Prussia and drive on eastern Germany by the Soviet Union and the continued advance into northern Italy. In the Pacific, a serious of campaigns had reclaimed many of the territories occupied by the forces of Imperial Japan, while isolating many others. There was little doubt as to which side was going to be the final victor, it was just a question of how many more people would die and where the final battle would be.
The Allied advance across the Pacific entailed two major thrusts and a subsidiary one. The subsidiary one was a combined American / Canadian advance that had cleared the Japanese from the Aleutian Islands and was looking to move southwest. In the Southwest Pacific Area, General Douglas MacArthur with a combined force of US Army, US Marines, Australians and New Zealanders had seized the Solomon Islands, then New Britain and advanced along New Guinea's northern coast towards the Philippines. MacArthur invaded Leyte on 20 October 1944 and Luzon on 9 January 1945, with the support of the Third and Seventh Fleets and land-based aircraft. The Philippines were finally declared secure on 5 July 1945, two weeks after Okinawa. In the Central Pacific Area, the Fifth Fleet, supported by carrier-based aircraft had secured the Gilberts in late 1943 and neutralised the Japanese strongholds of Rabaul and Truk. They seized the Marshalls in early 1944, the Mariana Islands by the end of August 1944, the Palau Islands by the end of November 1944, and Iwo Jima by the end of March 1945. The seizure of the Marianas (given to the Japanese as Mandates in 1919 by the League of Nations as former possessions of Imperial Germany) was a serious blow to the Japanese who considered them to be a key part of the Empire. It caused such an outcry as to force the then Prime Minister General Shigenori Tojo to resign and a new cabinet to be formed.
It was obvious to everyone what was coming next. For the invasion of the homeland, the Japanese knew the Americans would need a large base as a staging post from which to strike. On the other side, the Americans knew that an attempt to land on the main Japanese islands (the overall codename for which was Operation Downfall) would be met by several million soldiers, militia and civilians all of whom would offer fanatical resistance in the same vein as Tarawa, Peleliu and Iwo Jima. Careful preparation and a large logistical base were therefore necessary. The question was, would it be Formosa off the coast of mainland China or would it be Okinawa, part of the Ryukyu Islands?
