A look at the end of WWII if the atom bomb was not dropped (part 1)

     Deep in the recesses of the National Archives in Washington D C, hidden for nearly four decades, lie thousands of yellowing and dusty documents stamped "Top Secret". These documents, now declassified, are the plans for "Operation Downfall", the invasion of Japan during World War II.
     Only a few Americans in 1945 were aware of the elaborate plans that had been prepared for the Allied invasion of the Japanese home islands. Even fewer today are aware of the defenses the Japanese had prepared to counter the invasion had it been launched.
     Operation Downfall was finalized during the spring and summer of 1945. It called for two massive military undertakings to be carried out in succession and aimed at the heart of the Japanese Empire.
     In the first invasion, code named Operation Olympic, American combat troops would land on Japan by amphibious assault during the early morning hours of November 1, 1945. Fourteen combat divisions of soldiers and marines would land on heavily fortified and defended Kyushu, the southernmost of the home islands after an unprecedented naval and aerial bombardment.
     The second invasion, code named Operation Coronet, would send at least 22 combat divisions against 1 million Japanese defenders on the main island of Honshu and the Tokyo Plain. Its goal: the unconditional surrender of Japan.
     With the exception of a part of the British Pacific Fleet, Operation Downfall was to be a strictly American operation. It called for using all of the Infantry Divisions in the Pacific area, the entire Marine Corps, the Pacific Navy and elements of the 8th Air Force (recently deployed from Europe), the 20th Air Force and the American Far Eastern Air Force.
     More than 1.5 million combat soldiers with 1 million more in support. More than 40 per cent of all servicemen still in uniform in 1945 would be directly involved in the two amphibious assaults.  Casualties were expected to be extremely heavy.
     Admiral William Leahy estimated that there would be more than 250,000 Americans killed or wounded on Kyushu alone. General Charles Willoughby, chief of intelligence for General Douglas MacArthur, the Supreme Commander of the Southwest Pacific, estimated American casualties from the entire operation would be 1 million men by the fall of 1946.
     During the summer of 1945, America had little time to prepare for such an endeavor, but top military leaders were in almost unanimous agreement that an invasion was necessary.
     So on May 25, 1945, the Joint Chiefs of Staff, after extensive deliberation, issued to General MacArthur, Admiral Nimitz, and Air Force General Henry Arnold the top secret directive to proceed with the invasion of Kyushu. The target date was set for after the typhoon season.
     President Truman approved the plans for invasion on July 24. Two days later, the United Nations issued the Potsdam Proclamation which called upon Japan to surrender unconditionally or face total destruction. Three days later, the Japanese government broadcast to the world that Japan would ignore the proclamation and would refuse to surrender. 
     During this same period it was learned that Japan had closed all schools and mobilized its school children, was arming its civilian population, was fortifying caves and was building underground facilities. 
     Operation Olympic called for a four-pronged assault on Kyushu. Its purpose was to seize and control the southern one-third of that island and establish naval and air bases to tighten the naval blockade of the home islands, to destroy units of the main Japanese Army and to support the later invasion of the Tokyo Pain. 
    The preliminary invasion would begin on October 27, 1945 when the 40th Infantry Division would land on a series of small islands west and southwest of Kyushu. At the same time, the 158th RCT would invade and occupy a small island 28 miles south of Kyushu. 
    On these islands, seaplane bases would be established and radar would be set up to provide advance warnings for the invasion fleet, to serve as fighter direction centers for carrier-based aircraft and to provide an emergency anchorage for the invasion fleet, should things not go well on the day of the invasion. 
    As the invasion time becomes imminent, the massive power of the Navy (the Third and Fifth Fleets) would approach Japan. During the early morning hours of November 1, the invasions would begin. Thousands of soldiers and marines would pour ashore all along the eastern and southeastern, southern and western coasts of Kyushu. Waves of Helldivers, Dauntless dive bombers, Avengers, Corsairs and Hellcats from 66 aircraft carriers would bomb, rocket and strafe enemy defenses, gun emplacements and troop concentrations along the beaches. 
    The Eastern Assault Force consisting of the 25th, 33rd and 41st Infantry Divisions would land near Miyasaki, at beaches called Austin, Buick, Cadillac, Chrysler and Cord. They would move inland to attempt to capture the city and its nearby airfield. 
    The Southern Force, consisting of the 1st Calvary (including the 44th Tank Battalion), the 43rd Division and Americal Division, would land inside Ariake Bay at beaches labeled DeSoto, Dusenberg, Essex, Ford and Franklin and attempt to capture Shibushi and the city of Kanoya and its airfield. 
    On the western shore of Kyushu, at beaches named Pontiac, Reo, Rolls Royce, Saxon, Star, Studebaker, Stutz, Winton and Zephyr the Amphibious Corps would land the 2nd, 3rd and 5th Marine Divisions, sending half its forces inland to Sendai and the other half to the port city of Kagoshima. 
    On November 4, the reserve force, consisting of the 81st and 98th Infantry Divisions and the 11th Airborne Division, after feigning an attack on the island of Shikoku, would be landed - if not needed elsewhere - near Kaimonadake, near the southernmost tip of Kagoshima Bay, at beaches designated Locomobile, Lincoln, LaSalle, Hupmobile, Moon, Mercedes, Maxwell, Overland, Oldsmobile, Packard and Plymouth.   
    All along the coast east of Tokyo, the American 1st Army would land the 5th, 7th, 27th, 44th, 86th and 96th Infantry Divisions along with the 1st, 4th and 6th Marine Divisions. At Samgami Bay, just south of Tokyo, the entire 8th and 10th Armies would strike north and east to clear the long western shore of Tokyo Bay, and attempt to go as far as Yokohama. The assault troops landing south of Tokyo would be the 4th, 6th, 8th, 24th, 31st, 32nd, 37th, 38th and 87th Infantry Divisions along with the 13th and 20th Armored Divisions. 
    Following the initial assault, eight more divisions - the 2nd, 28th, 35th, 91st, 97th and 104th Infantry Divisions and the 11th Airborne Division - would be landed. If additional troops were needed, as expected, other divisions redeployed from Europe and undergoing training in the United States would be shipped to fight in Japan in what was hoped to be the final push.