The first crucial issue confronting American leaders without nuclear weapons would be the prospects for Olympic. While Truman had initially approved Olympic in June, this was before the shocking intelligence revelations on Japanese preparations. Moreover, he singled out the fact that the Joint Chiefs had unanimously supported the operation as a key reason for his sanction. Even with MacArthur and Marshall’s obdurate support, if the navy withdrew its endorsement, and the radio intelligence picture appeared so bleak, Olympic could not have survived a second review by Truman. Moreover, the ULTRA portrait of Japanese ground deployments to greet Coronet was equally appalling. Chances are zero that either of these operations would have been executed in 1945.
The two obvious alternatives to invasion were diplomacy and the blockade and bombardment strategy. With the possible exception of Joseph Grew, the assistant secretary of state, however, no senior American policy maker was likely to press for negotiation since the minimum Japanese position involved the preservation of not just the imperial system, but of the old order that produced the war. Intelligence analysts had expressly warned policy makers on July 27 that so long as the Imperial Army remained convinced of its success in Ketsu Go, there was no prospect that Japan would yield to terms America could abide. It is vastly more likely that policy makers would have switched their attention to blockade and bombardment and just at that moment they would have learned the prospects for that strategy were waxing dramatically.
In May 1945, a survey team from the United States Strategic Bombing Survey (USSBS) mounted a whirlwind investigation of Germany to derive lessons that could be applied against Japan. The USSBS party concluded that attacks on oil production and the Reich’s transportation system had “contributed in decisive measure to the early and complete victory.” Added to the very dim American understanding of Japan’s war economy, this in formation triggered a fundamental change in the direction of the strategic bombardment program in the Pacific.
On August 11, 1945, Major General Curtis LeMay, who was then the chief of staff for General Carl Spaatz, the commander of United States Strategic Air Forces, Pacific, promulgated a new targeting directive. Under Spaatz’s command were the Twentieth Air Force, based in the Mariana Islands, and the Eighth Air Force, redeploying from Europe to Okinawa. For the over 1,200 B-29s these two air forces would field by October 1, 1945, the directive listed a total of 219 targets. The new blueprint drastically curtailed the program of systematic incineration of Japan’s cities begun in March and instead gave top priority to fifty-six railway yards and facilities and thirteen bridges that formed the core of Japan’s land transportation system. Then came targets in the aircraft industry, munitions storage, and thirty-five urban industrial centers.
On cursory inspection, this new directive appears far more satisfactory as a means of reducing noncombatant casualties than city burning. But its actual effect would have been to inflict a catastrophic mass famine. In 1945, three of four Japanese resided on Honshu, the largest of the four main home islands. Nearly half the total population clustered in the south-western half of that island. Japan harvested the great bulk of her food on Hokkaido, northern Honshu, and parts of Kyushu. The annual rice harvest in September and October marked the crucial event in the food supply. A host of factors tumbled the rice production from over 10 million tons in 1942 to only 6.3 million tons in 1945.
Japan customarily bridged the gap between domestic food production and need with imports, but the destruction of her merchant fleet virtually extinguished that source by August 1945. The collapse of the water transportation system threatened even more dire peril. Unlike any other major industrialized nation, Japan relied upon seagoing transportation for domestic as well as international trade. If Japan lacked ships to haul food from surplus to deficit areas, her only alternative was her railway system. That system, however, was limited and extraordinarily vulnerable to air attack. Postwar study by USSBS calculated that a mere half-dozen cuts of the major net along the Pacific coast of Honshu would have incapacitated the whole system. The B-29 force, not to mention carrier-based aircraft, would have inflicted many times this damage in a few days. Destruction of the railroads would have been cataclysmic. After the surrender in August 1945, as it was, Japan tottered through the 1945–1946 Rice Year in desperate shape. The food ration officially dropped to 1,042 calories per day in Tokyo by May 1946. This was with functioning railroads and a civil administration in place. The effects of the new air-targeting directive would have first struck Japan’s heavily industrialized and populated region along the south-western rim of Honshu. These cities filled the rice needs of their populations with shipments. Tokyo, the worst case, met only 3 percent of requirements from local growers. Without water or rail transportation, these teeming centers would have swiftly depopulated, sending millions of hungry refugees swarming into the countryside. Not only would this have brought the collapse of industrial production, it also would have unhinged the civil government, essential to ration and distribute the available food. By late spring of 1946, all food supplies in the south-western half of Honshu would have been consumed. This would have compelled the weakened survivors of what was originally half the nation’s population to migrate in search of food, or perish.
The resulting tragedy would have engulfed the Japanese and other peoples in a catastrophe. Millions would have perished in Japan from starvation or disease due to the famine during the 1945–1946 Rice Year. The vastly diminished population of Japan would have been reduced for years to a crude rural subsistence-level existence stalked by the continual ravages of a food shortage. Moreover, all of the Allied prisoners of war and civilian internees in Japan would have perished—as would millions of others. Most, if not all of the two million Japanese under arms outside the homeland would have held out until annihilated by battle, disease, or starvation. With them would have died millions of noncombatants throughout Asia. The Allied prisoners of war and civilian internees would have shared the fate of their peers in Japan, bringing the total deaths in this category to over 300,000.