The Invasion of Japan: Alternative to the Bomb

Book review by David Lee

The Invasion of Japan: Alternative to the Bomb
By John Ray Skates
University of South Carolina Press, 1994

This year (2025) marks the 80th anniversary of the end of World War II. There was much celebration by the winners, which included Russia, China, the US and the UK. By contrast, there was no celebration by the losers. In Germany, Victory in Europe (V-E) Day was marked with solemn, official remembrance. In Japan, officials marked August 15, the day of acceptance of the July 26, 1945 Potsdam Declaration, with tributes to Japanese civilians and soldiers who were killed in World War II.
Americans also celebrated their August 1945 limited nuclear war against Japan because, they are repeatedly told, this forced Japan to surrender. The only other alternative to nuclear attacks on Japan, Americans are further reminded, was an amphibious assault on the Japanese homeland which would have resulted in “a million” American casualties. Americans are also reminded that given the “fanatical and suicidal” Japanese culture, the nuclear attacks on Hiroshima and Nagasaki were the “right choices,” to avert not only an American bloodbath but to “save” the Japanese nation. University of Southern Mississippi professor emeritus of history John Skates (1934-2009) points out, for an event that never happened, the planned American amphibious assault on the Japanese home islands has “provided some of the major undergirdings for widely accepted interpretations about the end of the war against Japan.”
Skates’ book is one of the first in the English language to detail not only American preparation and planning for an amphibious assault that would have greatly dwarfed that of Normandy in scale but also shows what Japan’s plans were to counter such an attack and realistically assess Japan’s defenses. Skates also spends considerable pages describing conflicting personalities between key American military planners, such as Commander in Chief, Pacific Fleet Admiral Chester Nimitz and Commander in Chief, Army Forces Pacific General Douglas MacArthur, among others.
For example, MacArthur, described by Skates as having a “streak of paranoia”, believed that the Navy “was conspiring to freeze him out of “their” Pacific war…” and leaving him in a secondary, supporting role. Opinions differed among key military planners for the necessity of an invasion of the Japanese home islands. MacArthur was of the “unequivocal” opinion that there will be an invasion of Japan and furthermore that he would be overall commander. By contrast, Skates describes Nimitz as “affable and self-effacing”. In contrast to MacArthur, Nimitz was not “paranoid or suspicious” of the motives of the Pacific military commanders. While initially hoping, possibly believing, an invasion was not necessary, due to the efficacy of the naval blockade of Japan, he later changed his mind and came over to MacArthur’s side.
Skates goes into fascinating details, of deadly serious consideration by Americans of the use of poison gas during the invasion against entrenched Japanese defenders and to further weaken an imports-dependent Japan by spraying Japan’s rice crops with herbicides. Army Chief of Staff George Marshall is quoted saying that “There would be nine more atomic bombs…” ready by the “first landing on the southern tip of Japan,” which was scheduled for November 1. Some would be used on the invasions sites prior to the arrival of American soldiers and some would be used against “defensive positions further inland” or for “counterattacking forces attempting to move to the beach head.”
With respect to American use of nuclear weapons, the conventional wisdom states that options to induce Japan to accept the Potsdam Declaration (i.e., “unconditional surrender of all Japanese armed forces”) rested in either the invasion of Japan or nuclear attack. However, Skates points out that while the Pentagon drew outlines for the invasion of Japan in “mid-1944”, no one, including the “Pacific commanders charged with the final planning and conduct of the invasion,” MacArthur and Nimitz, knew anything about the atomic bomb project nor “took any account of it in their work.”
President Franklin Roosevelt and Prime Minister Winston Churchill demanded Japanese “unconditional surrender” at Casablanca in January 1943. As part of planning in mid-1943, US Joint Chiefs rejected British military plans against Japan. The British, keen on keeping American troops in Europe long after Germany’s defeat, envisioned Allied operations against Japan in 1947. Considering American war weariness and troop morale, the US Joint Chiefs proposed to defeat Japan within 12 months of V-E Day through a combination of air bombardment and sea blockade of Japan—with an invasion if these measures failed to bring about the “unconditional surrender” demanded by Commander in Chief Roosevelt. Indeed, despite intensive discussion within the Joint Chiefs, who viewed “unconditional surrender” as a strategic impediment, and with American political leaders, including President Roosevelt, “unconditional surrender remained the chief Allied policy regarding the defeat of Japan, and the Joint Chiefs had to construct a military strategy that fulfilled that policy.”
Interestingly, Skates mentions early joint US-British war plans against Japan included major operations with Chiang Kai-shek’s army and a potential joint American, British and Chinese invasion of Japan. As for Chiang’s involvement in the war against Japan, as Skates notes, the British “had little faith in Chinese abilities or their will to fight…” Furthermore, as events unfolded in 1943, it was clear that Chiang “could not be counted upon to bear the brunt of the ground war against Japan.” Thus, Operation Downfall, the overall invasion plan that included Kyushu (Operation Olympic) and the Kanto Plain (Operation Coronet) was to be entirely all-American.
The American war plan against Japan by the summer of 1945 proceeded pretty much as envisioned. “Japan faced imminent starvation for its industry and people.” Due to US carpet bombing, “174 square miles in 66 [small] cities were burnt out and an estimated 330, 000 Japanese were incinerated.” Air delivered sea mines immobilized Japanese channels and harbors—the “shipping situation was hopeless”. Japan lost her ability to resupply her overseas military and lost air superiority over the homeland. Almost all of Japan’s navy was sunk at the Battle of Leyte Gulf in October 1944. While blockade and bombardment were progressing, if these did not move Japan to “unconditional surrender”, then “the invasion of southern Kyushu,” to secure more bases to “tighten the blockade and intensity the air bombardment,” “would go forward.”
Despite a gloomy strategic position and eventual loss, the Japanese were able to extract heavy casualties in the defense of Luzon and Okinawa. Special attack units (so-called kamikaze) were thrown at US naval vessels in large numbers. American military planners were grimly aware that as the Americans moved closer to Japan that the casualty list would lengthen.
The conventional wisdom, that Japanese fanaticism opposing an American amphibious assault would lead to a “million” American deaths, is based in part on post-war claims. For example, President Truman claimed that the invasion “…might cost as much as a million, on the American side alone…”. Skates shows us that Truman also stated the invasion of Japan would have costed “250,000 casualties” and then “half a million American lives.” Winston Churchill chimed in to claim that half a million British lives would have been lost in an invasion of Japan.
Perhaps this is yet another example of Churchillian bloviation. (He also had uncomplimentary comments about nonwhite people. ) MacArthur, overall commander of army units for Operation Coronet, the March 1946 invasion of the Kanto Plain, at first rejected British offers of five army divisions for the initial assault. Instead, he suggested, three British-Commonwealth divisions (British, Canadian and Australian). These would not participate in the initial assault but be held has reserves. At the time, one British infantry division consisted of about 18,000 men. US military planners at the time accepted Allied offers of participation purely out of diplomatic courtesy and not out of military necessity. American military leaders stated that significant differences between US and other Allied militaries in terms of doctrine and supply requirements would lead to battlefield and logistical confusion.
American casualties would be in line with previous experience. Even with attrition-type warfare employed by the Japanese overseas during the late stage of the war, American military planners believed that with an invasion of Kyushu, they would have tactical advantages such as “maneuver room for land and sea operations” which did not exist, for example, in Okinawa. Casualty estimates, Skates states, “were realistic and based on past experience.” MacArthur’s planners initially estimated a total of 22,576 casualties, including dead and wounded, within the first 30 days of Operation Olympic.
The Joint Chiefs were to brief President Truman on the invasion of Japan on June 18, 1945. Asked for casualty estimates to present to Truman, MacArthur replied that 50,800 casualties could be expected during the first 30 days of Operation Olympic. (According to Skates, MacArthur did not explain the upwardly revised figure.) During Truman’s briefing, Skates noted that the Joint Chiefs “refused to estimate precise numbers” when Truman asked about casualties. However, the Joint Chiefs did state that casualties for the first 30 days in Kyushu “should not exceed the price we have paid for Luzon.” Luzon “resembled Kyushu”, in size and terrain. In the Luzon campaign, there were 37,870 American casualties, including 13,160 killed in action and 2,934 who died of wounds. At the end of the briefing, Truman “approved the decision to go ahead with Olympic…”
While we will never know if Operation Olympic or all of Operation Downfall could have led to “one million” American casualties, this figure is a post-war exaggeration not based on the figures given at the time. This leads one to consider what in fact would US troops have faced on its amphibious assault of Kyushu?
The Japanese had given little thought to the defense of the home islands. Skates mentions that it was not until mid-1944 that the Imperial General Staff ordered comprehensive evaluation of homeland defense in light of American advances and Japanese military losses in the southwest and central Pacific. Skates tells us that planning a defensive operation was “difficult” since Japanese officers were “trained to think exclusively of offensive warfare.” Nonetheless, Japanese planners envisioned a costal defense, utilizing whatever military forces were available within the homeland to prevent American establishment of beach heads on Japanese soil. After the fall of Okinawa, Japanese military planners identified Kyushu, for a number of tactical reasons, as the potential target for an American amphibious assault. Close quarter combat between American and Japanese troops on Kyushu beaches, Japanese planners hoped, would prevent American use of air support and naval guns. Furthermore, southern Kyushu’s mountainous terrain would be an advantage to the Japanese defenders and work against the American invaders.
Japan’s actual defensive state late in the war, as Skate shows, does not encourage optimism. Japanese construction of fortifications began in the “fall of 1944,” but steel and cement were in short supply. Construction of planned defensive structures remained incomplete by the end of the war. Japanese military leaders sought to mobilize more than two million for homeland defense. Mobilization began in the middle of 1945. Because of US carpet bombing and sea blockade, mobilization further strained already deteriorated Japanese logistics and supply networks. With respect to manpower, Skates states, “Some units reported to their commands without weapons or adequate training” and furthermore, experienced officers and specialists, necessary for intra-unit cohesion and inter-unit coordination, were in short supply. Skates cites a Japanese staff officer, who stated that the majority called up in the final mobilization were “either untrained or old.” Japanese naval forces at the time were either mostly at the bottom of the Pacific, “damaged or immobilized for lack of fuel.” What aircraft or ship that could move was saved for the “final devastating blow” envisioned by Japanese planners: massive kamikaze attacks against the American invaders.
Indeed, Japanese planner “estimated that they could have ten thousand planes available at the time of the invasion [of Kyushu] …” Other units consisting of small fast boats, midget submarines and manned rockets and torpedoes were to be utilized against the Americans. Viewing post-war records, it is doubtful that there were “10,000” operational planes available within Japan. By 1945, Japanese planes were inferior in design compared to American planes. Because of fuel shortages, flight training was curtailed. Also, due to US air attacks, Japanese airplanes were dispersed throughout Japan for protection and due to a shortage of radios, it would have been difficult to coordinate between air and ground attacks. Thus, the envisioned massed kamikaze “crippling blow” attack against off-shore American forces would have been extremely difficult at best.
Finally, despite propaganda believed by both war-time Japanese militarists and most modern American historians, there was no defined military plan to use Japanese civilians as weapons against the Americans. In fact, Skates points out, military leaders planned to evacuate civilians from potential battle zones in Kyushu. Evacuation however was seriously hampered, thanks to US devastation of roads and communication links as well as the lack of fuel within Japan for any operating vehicles. Movement out of mountainous southern Kyushu would have been by foot with horse-drawn wagons. (For the Japanese army, they would have faced the same challenge moving into southern Kyushu to face the Americans.)
Another key point raised by Skates that mainstream historians have repeatedly denied is the fact that Japanese leadership tried to end the war well before the Potsdam Declaration. Skates notes that “during the summer of 1945”, the US government was well aware of people within the Japanese government were seeking to end the war. However, Skates also notes that contacts were informal, “neither authorized or sanctioned by the Japanese government.” Skates lists meetings between Japanese representatives and Americans and the Swiss, but there were other contacts and a commitment by the Emperor himself to seek an end to the war during this period. In early 1944, there were discussions within the Japanese government to replace Prime Minister Tojo Hideki with a cabinet that would immediately seek peace with the US. In May 1945, the Japanese cabinet openly discussed and sought peace mediation by the Soviet Union, with which Japan had signed a five-year Non-Aggression Pact. In June, the Emperor quietly approved of a plan to end the war and former foreign minister Hirota Koki discussed mediation for peace with the Soviet Ambassador to Japan. Unknown to Japan, however, the Soviets had previously agreed with Roosevelt to attack Japan within “two or three months after Germany has surrendered.”
While Skates’ book is an impressive narrative of Japanese as well as American preparations for perhaps the largest military operation ever that never happened, it does contain at least one error. Skates claims that breaking the Japanese diplomatic codes, American codename “Magic”, were a failure, in that breaking the code could “have revealed the plans for the attack on Pearl Harbor.” In fact, Americans broke the “Magic” code in September 1940 and key Roosevelt Administration officials, including Roosevelt himself, read the decrypted messages. For example, during the period of negotiations prior to Pearl Harbor, the US abandoned compromising with Japan while Japan sought some diplomatic leeway from the US. During this time, Secretary of State Cordell Hull “usually knew what was on [Japanese Ambassador] Nomura’s [Kichisaburo] before he walked into a conference.” Decoded Magic messages clearly stated Japan’s intention to break diplomatic relations should negotiations fail. What is not clear though is if the appropriate people within the military were informed, which could have alerting them to a potential first strike on Pearl Harbor. Various motives, or perhaps sheer ignorance, have been proposed as reasons for this failure in intelligence, but Magic itself worked as expected.