Travis Weninger

Dec 27, 2019

13 min read

Truman’s Decision to Drop The Atomic Bomb

Photo of the Atomic Bomb from the Trinity Test Site

Due to the extremely top-secret nature of The Manhattan Project upon beomcing president learning about the project was a surprise to Harry S. Truman. The War in Europe was over with an Allied victory and pressure from the American public to bring the boys home was building, the only battles left to fight remained in The Pacific. After Japan had launched a surprise attack on the American Naval Base at Pearl Harbor in 1941 the US had been engaged in fighting another deadly front for several years. Inevitably the war will end with The United States dropping two atomic bombs on the Japanese cities of Hiroshima and Nagasaki along with The Soviet Union declaring war on Japan forcing them to surrender. Truman was faced with one of the most difficult decisions a man has had to make in all of history, there were many factors and people that influenced this decision as it was not something he decided over the flip of a coin. The decision to use atomic weapons had short term and long reaching implications that had to be equally considered in the process. This topic has been hotly debated by historians for years with many different theories on the real reasons behind the decision and as is seen with many other themes in studying intelligence operations, sometimes the right information just doesn’t reach the people it needs to.

Harry S. Truman transitioned from vice president to president in April of 1945 after Franklin D Roosevelt passed away due to a cerebral hemorrhage. Truman was a man of humble beginnings being born into a family of farmers in Missouri and not exactly what would come to mind for most people when thinking of a potential president. When Truman grew up, he explored various business ventures that mostly failed, joined the Missouri National Guard, and fought in WW1 seeing active duty. After the war he remained in The National Guard and caught the attention of Roosevelt when he led a committee that investigated corruption in military spending. Through this committee he uncovered billions of dollars in fraudulent and wasteful military spending, this led Truman to become Roosevelt’s running mate in 1944. Roosevelt and Truman won the election and were in office together for 82 days before Roosevelt passed away. Truman becoming president was seen as a victory for the common man as he was an honest person that wasn’t a career politician. Prior to Truman becoming President he had absolutely no idea about The Manhattan Project or the grave decisions he would be faced with in the coming months.

Logo for the top secret Manhattan Project

The Americans fight against the Japanese was deadly by all accounts. The Japanese did everything they could to hold off the Americans as long and hard as possible. The strategic tactics they used for defence like constructing miles of tunnel networks in mountains and fortifying high ground forcing the Americans to invade from beaches turned these battles into a slaughter. Two major battles help paint the picture of how dedicated the Japanese were to inflicting as much carnage on the Americans as possible, these are the Battle of Iwo Jima and The Battle of Okinawa.

Iwo Jima was a fortified volcanic island that housed 24,000 Japanese troops. Due to the mountainous geography of the island and the Japan’s radar technology B29 Bombers were not able to fly over and drop bombs that would aid the Americans in battle. The Japanese had created 23 miles of tunnels through the mountains of the island and build 1,600 fortified bunkers. In an effort to break up some of these fortifications and tunnels the Americans shot 22,000 heavy shells at the island from warships to try and make the invasion easier. When the Americans decided to invade 566 men were killed, 1,755 wounded, and 99 diagnosed with combat fatigue on the first day. The battle lasted for 5 weeks and by the end 27,499 Americans had been killed. The lesson learned in this battle was that Americans had grossly underestimated the strength of the Japanese by 70% and the loss of American life by 80%.

The Battle of Okinawa was even bloodier than Iwo Jima with 80,000 Japanese ready to fight and 120,000 civilians who strongly supported the military. The Americans invaded with 1,500 ships and 180,000 soldiers, the first US advance was totally unopposed by the Japanese as they decided to only defend high ground in this battle. Japanese commanders knew that defending the island of Okinawa was not going to work in their favour, so they decided that their strategy was to make the Americans pay the highest price possible to take the island in resources, time, and lives.

As the Japanese continued to fight their resources were quickly depleted but they still needed to inflict as much damage on the Americans as they could. This battle is where we see the birth of Kamikaze pilots. These men believed in the Bushido Code which dates back to the heritage of a Samurai way of life. The Bushido Code means that these men are willing to make the ultimate sacrifice for their emperor and country. With this code guiding them, poorly trained volunteers were thrown into fighters and instructed to fly into American ships, sacrificing their lives and planes for their country. By the end of The Battle of Okinawa The Army and Navy combined will have 11,920 killed, 39,119 wounded, and 26,211 psychologically wounded. These numbers are staggering and when they reached back home the media harshly criticized the tactics and motives behind the battle seeing it as a waste of life. It is known that Truman saw The Battle of Okinawa as a preview of what was to come if the Americans did launch a ground invasion on Japan. Based on knowledge of how The Battles of Iwo Jima and Okinawa ended, the military made the conclusion that if The US were to launch a ground invasion called Operation Olympic on the Japanese island of Kyushu the American causalities were estimated to be around 500,000–1,000,000. Kyushu is the most southern main island of Japan and at the time and had a population of 10 million people, 300,000 of those being soldiers. The biggest city in Kyushu was Nagasaki with a population of 350,000. As planning and time passed the Island would come to house around 900,000 soldiers. The first phase of Operation Olympic involved a land invasion with 650,000 troops followed by Operation Coronet which would send another 22 combat divisions to take on a remaining 2 million Japanese defenders. This whole effort would require the entire US Marine Corps, the entire US Navy, and four air forces totalling 1.5 million combat soldiers.

Famous photograph of the American flag being raised after the deadly Battle of Iwo Jima

If the fighting wasn’t enough the tactics the Japanese were prepared to use to fight off an invasion were just as troubling. American Intelligence learned from a communication intercept that the Japanese had shut down all their schools and were training children to fight against the invasion. The entire military and civilians were willing to die by the Bushido code. Through another communication intercept from the Japanese Palace, the Americans learned that the Japanese Imperial Palace had told their citizens if they died defending their homeland, they would enjoy the same glorious after life as soldiers (158)5. The Japanese had another defence plan called “Ketsu-go” which aimed to destroy invading American ships before they reached shores. They planned to do this with people called Frogmen who would stay submerged in the water for 10 hours at a time and stick high powered explosives on the bottom of American ships. It is unknown if Truman was personally informed of the 500,000–1,000,000 causalities that would result in commencing Operation Olympic. General MacArthur’s staff even believed that the causalities would exceed 1 million. Even if he did not see the projections of one million American casualties, he understood it would be a blood bath based on what happened at Iwo Jima and Okinawa. Another f actor to consider was that if an invasion on Japan commenced the Japanese would execute the 168,500 allies that had been imprisoned. From observing the tactics, the Japanese used to defend the attack on Okinawa it was clear the US could win but the Japanese plan was to make it cost the most for Americans in time and lives.

To get an idea of how deadly a land invasion of Japan was projected to be the military ordered that 500,000 purple hearts be made to give to fallen soldiers. In the American Military the purple heart is one of the highest military honours and it is awarded to families of fallen soldiers or to those wounded in battle. An expected death toll is something that’s hard to imagine but seeing the production of half a million purple hearts really puts the loss of life in perspective. Some historians believe the production of these purple hearts was an effort to sway the decision in favour of dropping the atomic bomb because it makes it makes the facts more concrete. Half a million purple hearts are easier to comprehend than 250,000 dead, 150,000 wounded, and 100,000 missing. Nevertheless, the invasion did not happen, but it is assumed the purple hearts that were ordered to be made for the invasion are still being given to soldiers today.

When Truman came to his presidency, he had no idea of The Manhattan Project and its initiative in developing atomic bombs. To help Truman make the decision on whether to use atomic Bombs or not an Interim Committee was formed. The committee was made of Henry Stimson as chairman, a member from New York Life Insurance Co, a personal representative of The President James Byrnes, an undersecretary of the navy, and three scientists. There was also a panel of 4 scientists which included Robert Oppenheimer that the committee could consult. It is believed that this committee never seriously considered not using the bomb but just on how to use it. Byrnes was outspoken of his fear that the Soviets would develop a bomb before them.

Robert Oppenheimer

The science community was divided on the use of The atomic bombs they had been developing. Throughout the course of The Manhattan project 2 billion dollars were spent with 120,000 people working across 37 different facilities making it the most expensive weapons research and development initiative in the war. The research was headed by Robert Oppenheimer an unlikely person one would expect to do this type of work as he closely studied Hinduism. Oppenheimer famously said after the first successful detonation of an atomic bomb that “I am become death, the destroyer of worlds” which is a line from the Hindu text Bhagavad-Gita. Oppenheimer held the belief that Japan had essentially been defeated and that dropping the bomb “mercilessly dramatized the inhumanity and evil of modern war.” It is important to note that the research from The Manhattan Project had started while the Americans were still fighting against The Nazis with the scientists under the impressions that their work was needed to defeat The Nazis and keep them from conquering the world. Although Oppenheimer felt the way he did about using atomic weapons against Japan he didn’t believe it was his place to give opinions on policy as he was a scientist. Oppenheimer believed in following his ordered and letting people more qualified than him make the more important decisions. Einstein had the same line of thinking as Oppenheimer stating that “Had I known the Germans would not succeed in producing an atomic bomb I would not have lifted a finger.”

The Interim Committee held a two-day long conference to reach a conclusion on using the bomb to present to Truman. At this time Germany had surrendered, The Battle of Okinawa was at its deadliest, and the first successful atom bomb test was seven weeks away. A doubt on the committee’s mind was that they were unsure if an atomic bomb would explode if dropped out of an airplane. Oppenheimer recommended that the subject of the bomb should be shared with the soviets without giving them key details, the committee rejected this recommendation. The committee considered they could warn that Japanese about the devastation the bomb would cause but feared in doing this they would move all American Prisoners of War to areas Americans were trying to target. After much debate the committee ultimately concluded the bomb would be dropped and agreed on three recommendations for its use. These recommendations were that it should be dropped as soon as possible, it should be dropped on a combined civilian and military target, and that it should be used without warning. The committee understood the fact that many civilians would be killed but did not see any realistic alternative. Truman was presented with the recommendations and agreed with the findings.

Outside of The Interim Committee various efforts were made by those involved in The Manhattan Project to convince them in not dropping the bomb. The Franck Report was made by James Franck who worked on the bomb in Chicago, in the report he details the moral, social, and political implications of the bomb. His key argument was the bomb should be used for long-term policy not short-term military gain and he urged that The Soviets be given a demonstration to avoid an arms race. This report was given to Henry Stimson to pass on to Truman but was seen by the Interim Committee and ignored. Scientist Leo Szilard petitioned the president to not drop the bomb and obtained signatures from 67 scientists working on the project, but Truman was at The Potsdam Conference and never received it. Lastly Leslie Groves got Karl Compton to create an opinion poll to be answered by people working on the project but in an act of deception he worded the options in the poll vaguely then spun his findings to conclude that 87% were in favour of dropping the bomb.

Churchill, Truman, and Stalin in Potsdam July 1945

In July of 1945 Stalin, Churchill, and Truman met in Potsdam, a city in occupied Germany for The Potsdam conference. This conference was to plan what was going to happen with the allied occupation of Germany, but another goal was deciding on a plan for the Japanese to surrender. On July 16th the first atomic bomb was successfully tested at The Trinity Site in New Mexico, before this test the atom bomb was a theory not a reality. Entering talks with this knowledge gave Truman an upper hand in conversations with him even stating that “it has taken a great deal off my mind.” The bomb was even more powerful than the Americans imagined, and the successful test made it much more likely the bomb would be used. On July 17th Truman met with Stalin and without telling him directly that they had achieved a successful test of an atomic weapon, he convinced Stalin to formally declare war on Japan in August. Truman knew that the Soviets declaration of war would greatly help their quest for an unconditional surrender.

Truman wrote home to his wife after meeting with Stalin saying, “I’ve gotten what I came for, Stalin goes to war August 15 with no strings on it.” This was a great success for Truman because he could get the Soviets to declare war on Japan without them ever having to fight, a combination of atomic bombs and the Soviets being against them would surely make them surrender unconditionally. Truman was excited by the fact that he would bring the boys home continuing in his letter that “we’ll end the war a year sooner now, and think of the kids who won’t be killed, that is the important thing.” In a meeting with Churchill after getting confirmation from the Soviets Truman told him that “The Japanese war might end much quicker than expected” and expressed his opinion that the Japanese had no military honour after the way they attacked Pearl Harbor. The fact that Japanese civilians were urged to fight and die defending their country must have made it easier for Truman to justify killing civilians as they would be attacking invading allied forces.

Throughout the entire decision making process, the Americans were insistent on Japan giving them an unconditional surrender. The main reason that the Japanese were opposed to this was because it would mean they would have to lose their emperor. Japan and the US both were not willing to budge on their terms. While Truman was weighing the options for dropping Atom Bombs or launching a ground invasion, he received a memorandum from former president Herbert Hoover. In the memorandum Hoover urged Truman to abandon an unconditional surrender and save American lives, Truman dismissed these suggestions. After the Potsdam Conference Japan had been served with a warning from the allies called the Potsdam Declaration which stated to surrender or “face prompt and utter destruction” but through MAGIC and ULTRA, US Naval Intelligence’s final evaluation was that these warnings did nothing and they were still unwilling to surrender.

Gar Alperovitz originally made the claim that the primary goal of dropping atomic bombs was to intimidate the Soviets. After the allies had defeated The Nazis eastern Europe was occupied by the Soviets and the Americans were uncertain what that would lead to. Using the atomic bomb as a tool of intimidation to other nations is referred to as atomic diplomacy and is a view that is debated by historians. Another view regarding the Soviets and the bomb is that if the bombs along with a Soviet declaration of war forced Japan into a surrender the Soviets would never actually need to fight in the pacific, in return having the Americans owe them nothing. Scientific committees warned against dropping atomic bombs without informing the Soviets in fear that it would start an arms race and if we look past World War 2 that is exactly what happened.

Aftermath of the Nuclear Bomb “Little Boy” that was dropped on the Japanese city Hiroshima

In the end Truman decided to drop Little Boy on Hiroshima august 6th, the Soviets declared war on Japan August 8th, and on August 9th the Americans delivered their final blow dropping Fat Man on Nagasaki. The two bombs killed around 200,000 people with a fury of physical and political violence inevitably forcing Japan into an unconditional surrender. Many factors influenced Truman’s decision in going this route with the biggest factors being that an invasion would have been deadlier, billions were already spent on the project, The Interim Committees excitement to use the bomb, US and British cooperation, and the impacts the bomb would have on American Soviet relations. It is difficult to speculate what would happen if the atomic bomb had not been dropped but what followed was a complete shift in the way the world deals with conflict today.