By the summer of 1945, Adolf Hitler and his Nazi troops had lost World War II. But, contrary to popular belief, the war was not over—the Japanese refused to surrender, and in the Eastern hemisphere, war raged on. Most people believe that in order to force the Japanese to surrender, Americans dropped the atomic bombs on Hiroshima and Nagasaki; and while this was the end result, the United States had a different plan beforehand—Operation Downfall . The months between the surrender of Nazi Germany and the Japanese surrender were filled with planning, preparation, and predictions. After a few aerial bombings of Japanese cities, President Harry Truman opted instead to drop the new A-bomb to save the lives of many American soldiers and sailors.

More emphasis is on Germany’s involvement with the war, mostly of Hitler’s internment camps, than on the Japanese being involved at all. However, while Germany was invading its neighboring countries such as Austria in 1938, Japan had been invading neighboring China since 1937 . Sharing a view of pro-communism, Germany and Japan had become military allies, forming World War II’s Axis powers (along with Italy). The countering counties, the Allies, consisted of the invaded countries and those hoping to put down this new movement by the Axis powers. The first involvement the United States had with World War II came as a direct effect of Pearl Harbor, in which the Japanese military air-bombed the unsuspecting inhabitants on the American naval base. The United States could no longer ignore the increasing battlefront that European countries were fighting, and with the declaration of war on Japan, entered into World War II on the Allied side. There it remained throughout the war, through the surrender of Germany in May 1945 to Japan’s final surrender.

Towards the end of World War II, the United States was adjusting to a new political situation. While Franklin D. Roosevelt had won the 1944 election, he died unexpectedly in office on April 12, 1945, leaving Harry Truman president of the United States. Despite his military and political background, Truman had been left uninformed of any major decisions regarding the war; including, ironically, the Manhattan project, which was developing the critical atomic bomb.

In the meantime, Chester W. Nimitz was adjusting to his new position in the military; he had, in December 1944, become a Fleet Admiral of the United States Navy, the highest position in the navy. Nimitz focused on the Pacific fleets; moving the headquarters from Pearl Harbor to Guam, persuaded air forces to conduct the successful Operation Starvation, and assisting the famous battles of Iwo Jima and Okinawa.

In addition to creating the Fleet Admiral of the United States Navy position, the United States had also created the new rank of General of the Army, appointed to George Marshall. Marshall himself was no newcomer to warfare, having military experience and an extensive background in military education. He had, by 1942, expanded the United States army by 40 times the number of men in 1939. Given his new position, Marshall focused on organizing the Army Air Corps for combat, which became essential for Operation Downfall. With his previous experience in European invasions, he turned to the Pacific, helping to coordinate the movements taking place there.

The most influential official from the war with Japan was American general Douglas MacArthur. Despite controversies over the attack on Pearl Harbor, where he ineffectively did nothing with the 8 hour warning Japan issued beforehand, he remained in control of the war in the Pacific. He proposed Operation Downfall and oversaw the following Japanese invasion, including the occupation of Japan afterwards.

Following the surrender of Germany, President Truman met with other Allied leaders to discuss the terms of post-war Europe (The Potsdam Agreement) and the continuing issue with Japan. On July 26, 1945, the Potsdam Declaration was issued, which outlined the terms of the Japanese surrender. If the Japanese still refused to surrender, they would face “prompt and utter destruction.” As Japan did not surrender, the Allied nations began discussing plans to force surrender. Operation Downfall was not agreed upon at this time; it was undergoing consideration, but officials were hesitant. Prior to the Potsdam Conference, the United States had been forming attacks against Japan. Most famous of these campaigns were Iwo Jima and Okinawa.

On February 19, 1945, the United States began its first invasion of Japanese land, hoping to secure the airfields for future attacks. It began shelling the island hours before landing on the beaches. At first there was no resistance, as Japanese General Kuriyabashi was waiting for the beaches to be filled with American troops. The Japanese had, in preparation, hid their heavy artillery inside Mount Suribachi, creating a nearly indestructible defense. For this, they could open the steel doors protecting the artillery, fire, and then immediately close the doors. In addition, Japanese troops had created an elaborate underground tunnel system, protecting themselves and allowing for an element of surprise when countering the American attack . The Americans had little cover, and due to the terrain, could not construct the famous foxholes for cover. U.S. Marines made charges into the island, suffering huge causalities but still making progress. While by the fourth day, February 23, the United States had control of Mount Suribachi, the mountain was still occupied by the Japanese—underground. In addition, U.S. Marines still had to gain control of the rest of the island, a campaign that took an additional three weeks. As the battle wore on, the Japanese began to run out of food and supplies, and started nighttime surprise attacks of the Americans. Finally, the Japanese were defeated and the island of Iwo Jima was declared secure on March 26, 1945, after 35 days of fighting. While initially believed to be of strategic importance, it resulted in little future use for the war with Japan. In fact, the total American casualties were greater than Japanese casualties; however, most American casualties were wounded men, while many Japanese were killed.

A month after the Battle of Iwo Jima began the United States began another attack for Japanese land. The Battle of Okinawa began on March 18, 1945. The Japanese were again prepared for the attack, and had a defense similar to Iwo Jima, with hidden artillery, caves and a distinct knowledge of the area. Fortunately, the United States was joined by other Allied countries, prominently the British. The British Naval Fleet hoped to keep airfields from being useful to the Japanese, to prevent Kamikaze attacks. These Kamikaze attacks were suicide missions from small Japanese aircraft, which purposely crashed into Allied ships, and, laden with explosives, demolished them. Okinawa was fought by land as well was sea, and Marines faced circumstances similar to Iwo Jima. The battle continued until late June. Considered to be the bloodiest battle of the war, more casualties were suffered at Okinawa than at the infamous D-Day invasion in Europe months earlier. Despite the immense casualties and destruction of U.S. ships and aircraft, Okinawa proved to be a strategic success, even more so than anticipated. The United States created a military base and used that for future attacks on the Japanese mainland, including airfields and fleet anchorage. Most importantly, the placement of Okinawa was perfect for Operation Downfall.

With the capture of Okinawa, U.S. commanders (Nimitz, MacArthur, and Marshall included) began to plan the invasion of the Japanese mainland. Hoping to force the Japanese Empire to surrender no less than a year after Germany, they wished to develop a plan to make Japan surrender as quickly as possible with the least American casualties possible . The concept was developed to have a direct, large-scale invasion of the Japanese mainland, without requiring smaller operations to gain control around Japan and then invade. Unfortunately, Japan’s physical nature had few locations suitable for a successful invasion, leaving the island of Kyushu as the most promising. With this in mind, the United States Army developed Operation Downfall. It would consist of two smaller operations, Olympic and Coronet . While Coronet would be the actual invasion, Operation Olympic would enable Coronet to take place.

Operation Olympic would do a few things. First, it would convince the Japanese that the Allies had opted to surround and attack Japan, rather than invade, thus providing a decoy; this portion was called Operation Pastel . It would also secure a few smaller, surrounding islands to be used as resources for the main invasion of Kyushu . Then, the southern third of Kyushu would be invaded and turned into a staging area for Operation Coronet. Control of Kyushu would also give Operation Coronet a valuable airbase, in addition to Okinawa. Okinawa itself would be used as an airbase for Operation Olympic. The operation would use resources already stationed in the Pacific, and any additional resources needed could be pulled from those scheduled for Operation Coronet. Operation Olympic was set to begin on November 1, 1945, and was predicted to last 90 days.

Operation Coronet was scheduled to begin a few months after Operation Olympic, on March 1, 1946 . The invasion would begin from two points on either side of Tokyo Bay; one, starting on the Boso Peninsula and the other on Sagami Bay. They would drive northward and inland, meeting in Tokyo. Coronet would use the Allied forces of Australia, Canada, and Britain would be used in addition to those from the United States.

As Kyushu was the most obvious place for an invasion to begin, the Japanese anticipated this attack. For this reason, Operation Pastel would take place. However, the Japanese planned an operation of their own, Operation Ketsugo. This operation would include Kamikaze attacks as well as protection of Kyushu areas susceptible to attack; the Imperial Japanese Navy was no longer effective. The Japanese initially developed the plan to defend Kyushu in the summer of 1945; but when the Battle of Okinawa lasted much longer than originally predicted, the Japanese assumed that Americans would not attack again until after the typhoon season. At this point, Japanese defeat was imminent. Ketsugo was not in place to be a victory; instead, it was supposed to create far too many American casualties for the Americans to carry out their operations. In hopes that the Allies would decide against an invasion, Japan could avoid surrender and an armistice could occur.

Compiling predictions for Operation Downfall proved difficult. Casualties were predicted based on prior experiences with Japan, in which battle had always been more brutal than anticipated. In addition to the increasing Japanese defense, casualty predictions were being changed based on opinions. Those against Operation Downfall predicted higher numbers, and those trying to convince others that it was necessary lowered their numbers. MacArthur, supporting Operation Downfall, claimed 50,800 in the first 30 days and 95,000 for the entire Olympic Operation. When Marshall and Truman were unimpressed with this high count, MacArthur claimed he doubted that casualties would get that high, and that number was merely for planning purposes. The number increased when the United States Navy was considered—MacArthur’s casualty count did not include potential Navy losses. While there werre over 10,000 Navy casualties in Okinawa, there hundreds more Japanese Kamikaze attacks aimed at the Navy prepared as a part of Operation Ketsugo. However, all reports differed—some would not even chance a prediction and instead included charts of known facts and lists of variables that would affect the casualty rate. Preparations were made; 370,000 Purple Hearts were being made in anticipation of those to be wounded or killed, and the medical staff of the Sixth Army (who were to invade Kyushu) were preparing for 98,500 dead and 295,500 wounded. While MacArthur continued to try to convince Marshall and Truman to go through with Operation Downfall, the most likely count would have been his original prediction of 95,000. Despite MacArthur’s lowering of this prediction, Truman was still reluctant.

With Japan’s rejection of the Potsdam Declaration on July 28, 1945, Operation Downfall seemed imminent. Despite this, and although the operation still scheduled to begin November 1, it was still undergoing major consideration by government officials. Alternate locations were being discussed, although Kyushu remained the most promising. The use of gas was being considered, as it would force the Japanese out of caves and underground tunnels. The Navy was preparing its ships and men for the invasion, taking volunteers for the “beach party.”

However, on July 17, 1945, the first Atomic bomb was tested near Alamogordo, New Mexico. As the Manhattan Project, which developed the bomb, had remained a large government secret, the use of nuclear weapons had not been considered with the war on Japan. Officials proposed using nuclear weapons in addition to Operation Downfall—naively assuming that Allied armed forces should not land any sooner than 48 hours after detonation.

Instead, President Truman decided to drop the first bomb, “Little Boy,” on August 6th, 1945. The intended target was the Japanese city of Hiroshima. The bomb initially killed 70,000 Japanese citizens, not including those that were later killed by the effects of burns and radiation. Japan still refused to surrender, and on August 9th, a second bomb was dropped on Nagasaki, a city located on northern Kyushu. The second bomb, called “Fat Man,” killed up to 75,000 citizens. More bombings were expected to take place in the following weeks. Nuclear weapons enabled the United States to wipe out entire cities in a matter of moments without any American casualties. However, Operation Downfall was still ready to go, if the bombings proved ineffective at changing the minds of Japanese officials.

As a result of the bombing, Japanese Emperor Hirohito accepted the terms of the Potsdam Declaration and surrendered on August 15, 1945. The official surrender took place on September 2, 1945, onboard the USS Missouri, when the Japanese Instrument of Surrender was signed. The document was signed by representatives of Japan and Allied countries, including Nimitz on behalf of the United States and MacArthur as the Supreme Commander for the Allied Powers.

Because of the surrender, Operation Downfall was no longer necessary. Americans never had to discover the number of casualties, and the Purple Hearts that were made are still part of the military surplus today . Although the use of the nuclear weapons and President Truman’s right to use them are still topics of controversy today, many regard the use of the atomic bombs as necessary in ending World War II. The men who were originally predicted to surely die in Operation Downfall were discharged and could return home unscathed, could all say one thing; “Harry Truman saved my life.”