Operation Downfall was the overall code-name assigned to the two planned invasions of the Japanese home islands: Operation Olympic, the invasion of Kyushu, scheduled for 1 November 1945 (X-Day); and Operation Coronet, the subsequent landings in Tokyo Bay, in the spring of 1946.
Earlier in the war, preliminary British studies had suggested that any such invasion would be impractical until 1947-1948 – but at the First Quebec Conference, on 17-24 August 1943, Allied leaders agreed that it should be scheduled for 1945-1946. The US Navy (USN) maintained, however, that there was no need for an invasion, which would risk heavy Allied casualties, and that Japan could be defeated instead by a naval blockade, supported by strategic bombing. The US Army strongly opposed this proposal, arguing that it could well increase Allied losses by prolonging the war indefinitely. Although the USN finally lost that argument, it still fought hard to dominate the operations’ command structure, claiming that there was no alternative to Admiral Chester W Nimitz, the commander of the US Pacific Fleet, as overall C-in-C, while the Army insisted on the post going to General Douglas MacArthur. Eventually, the USN reluctantly conceded MacArthur would take command.
The invasions were to be US-dominated from the beginning, with only limited Allied forces being involved. Primarily, these included: Admiral Sir Bruce Fraser’s British Pacific fleet, with six fleet carriers; the RAF’s Tiger Force, with more than 400 Lancaster heavy bombers (to be replaced with the new Avro Lincoln as it entered service); the Australian 1st Tactical Air Force, with 20 fighter and ground-attack squadrons; and the Commonwealth Corps (British 3rd, Canadian 6th, and Australian 10th Divisions), which was assigned to Operation Coronet.
