The World War II Memorial in Washington, D.C.
On April 12, 1945, President Franklin Delano Roosevelt, the man who had been president for over twelve years and led the United States through World War II, died. Harry Truman, the vice president, assumed the presidency at a time when important decisions about the war and the future of the world remained to be made. Upon becoming president, Truman learned of a secret program that could dramatically reshape the war against Japan and the future of humanity. Its purpose was to develop an atomic bomb capable of destroying entire cities and potentially the entire planet.
On August 2, 1939, one month before the start of World War II, Albert Einstein, one of the most brilliant minds of the twentieth century, wrote a letter to President Roosevelt at the urging of Hungarian-American Leo Szilard, to warn Roosevelt that research was being conducted in the worldwide scientific community on how to convert uranium into a prolific form of energy that could become an “extremely powerful bomb.” The letter goes on to warn Roosevelt that Nazi Germany was taking steps to harness uranium into a weapon and suggested that the United States government immediately fund researchers to do the same.
After the United States was brought into World War II with the bombing of Pearl Harbor by the Japanese on December 7, 1941, a secret government program was created to research, design, and build an atomic bomb. By September 1942, the Army Corps of Engineers took control of the program, named the Manhattan Project, under the direction of Brigadier General Leslie Groves. Such an undertaking required the expertise of the best minds in physics and science. Three secret sites in the United States were established. The first was in Oak Ridge, Tennessee, and its purpose was to enrich uranium to use in a bomb. The second was in Hanford, Washington, and its purpose was to enrich plutonium.
The third and most famous was at Los Alamos, New Mexico. It was here that the bombs were built and tested. J. Robert Oppenheimer led the Los Alamos facility. He was a professor at U.C. Berkeley who, through collaboration with another professor, Ernest Lawrence, gained new insights into nuclear physics. In June 1942, he was coordinating research on weapon theories for this new technology at a half-dozen universities throughout the country. General Groves asked Oppenheimer to lead a bomb laboratory on land in the remote New Mexico desert that eventually became Los Alamos.
Albert Einstein and Robert Oppenheimer
The Last Year of the War Against Japan
After years of brutal fighting and loss of American life in the war against Japan, only the complete defeat of Japan was acceptable to President Truman and the U.S. military. Leaving this Japanese government in place, after it had attacked the United States unprovoked, killed tens of thousands of American service members, and as many as 30 million people, mostly civilians, across Asia and the Pacific, was inconceivable. The idea of leaving Japan in control of the many countries and territories it had conquered in Asia and the Pacific region was not going to be tolerated. The only issue was how to conclude the war.
American Marines and soldiers fought across the Pacific in places such as Guadalcanal, Peleliu, Tarawa, Saipan, Iwo Jima, and the Philippines with the ultimate objective of reaching Japan itself. As the American manpower and manufacturing advantage began to decimate the Japanese military, the Japanese responded with more desperate tactics, which led to ever-increasing losses of life. The United States Navy began to face Japanese suicide planes, known as kamikazes, loaded with explosives and flown into American ships, starting with the Battle of Leyte Gulf in October 1944.
No matter how unwinnable the war became, there was a strong contingent within the Japanese military that would never accept surrender. Japan had never surrendered to a foreign power in its history and such a course was considered dishonorable. These leaders were more than willing to send Japanese soldiers and civilians, including millions of women and children, to their deaths rather than surrender to the Americans.
Air power and the use of bombers were new phenomena in warfare that significantly altered the way World War II was fought. By the end of 1944, the United States had air superiority in Japan, with thousands of B-29 bombers available to drop bombs by the end of the war. The Americans did just that in an effort to force surrender.
At the beginning of 1945, American bombers no longer exclusively focused on specific military targets, as they had earlier, but began to expand bombings to the neighborhoods where these targets were located. In March 1945, a fleet of American B-29s dropped close to 1,700 tons of incendiary bombs on Tokyo. The result was over 80,000 killed and hundreds of thousands injured after the numerous wooden structures in Tokyo caught fire, which spread through the city. Despite Japan being completely overmatched militarily at this stage of the war, American bombing only strengthened the resolve of hardliners within Japan’s military to continue the war.
In April 1945, the United States attacked the Japanese island of Okinawa, located about 340 miles from the Japanese mainland. The Americans wanted to use this island as a staging area for an attack against the home island of Honshu. As bad as the fighting had been to this point in the war, the Battle of Okinawa was even worse. After 82 days of fighting, 240,000 people were dead. The American casualties totaled 49,151, with 12,520 killed or missing and 36,631 wounded in action. The Navy lost 34 ships, 26 of which were destroyed by kamikaze attacks. For American military leaders and decision makers, Okinawa served as a reality as to what an invasion of the whole of Japan would look like.
American military planners had long been working on the invasion of Japan, known as Operation Downfall. The size and scope of this operation would have made it the largest in history, far larger than the D-Day invasion in Normandy, France. The invasion was tentatively planned for November 1945 and would have been preceded by a naval blockade and increased aerial bombardment. American soldiers who fought their way through Europe, at significant cost, and had already been subjected to heavy fighting against the Nazis, were going to be asked to redeploy and participate in the invasion of Japan. It was widely believed that if an invasion of Japan occurred, the thousands of American and Allied prisoners of war in Japanese custody would have been immediately executed.
The Japanese were training every able-bodied person to defend Japan, including women and children. During the Battle of Saipan in June 1944, American soldiers watched in horror as Japanese women and children committed suicide by jumping off cliffs into the ocean rather than be taken into American custody. They had been told the Americans would harm them. In reality, all Japanese civilians encountered by the Americans were given food, aid, and shelter. This, along with what the Americans experienced at Okinawa, led American planners to estimate potential American casualties to be as high as one million in an invasion of Japan. Japanese casualties would have been far higher than that and would have been mostly civilians.
However, after several years of planning, scientific research, and hard work, Robert Oppenheimer and the rest of his team at Los Alamos successfully tested the world’s first atomic bomb on July 16, 1945, in the New Mexico desert. It was ready to be used as a weapon of war.
President Truman learned of the successful test result while at a meeting with Soviet Premier Joseph Stalin and British Prime Minister Winston Churchill at Potsdam, a suburb of Berlin, Germany. There were two primary agenda items at Potsdam. The first involved what to do with Nazi Germany and the rest of Europe after the formal German surrender on May 7, 1945. The second concerned how to end the war against Japan. Truman informed Stalin about a “new weapon” he intended to use against Japan, but withheld the details. He also persuaded Stalin to join the war against Japan, and Stalin agreed because he saw this as an opportunity to expand Soviet territory.
On July 26, 1945, the Allies issued an ultimatum to Japan to surrender or face “prompt and utter destruction.” The Japanese refused. This set the stage for one of the most consequential decisions any leader in history has had to make: whether to drop atomic bombs on Japanese cities, leading to the deaths of tens of thousands of Japanese civilians.
The decision to use atomic bombs was fraught with ethical and moral considerations. The question for Truman was whether to use the new weapon against Japanese cities or to order the planned invasion of Japan instead. Both of these choices were perilous and would lead to significant losses of life. Truman understood the dilemma presented to him, saying, “It is an awful responsibility that has come to us.” He further added, “We shall in all probability have completed the most terrible weapon ever known in human history.” For him, the decision came down to saving American and Japanese lives and bringing the war to as fast a conclusion as possible. He believed the use of the atomic bomb was the best way to accomplish this.
Hiroshima, Japan, on August 6, 1945
After different scenarios were discussed about how to deploy the atomic bomb, including giving the Japanese a demonstration of the bomb before it was used against a Japanese city, President Harry Truman gave the order to use the atomic bomb against Japan. On August 6, 1945, Lt. Col. Paul W. Tibbets flew a B-29 named the Enola Gay after his mother, over the Japanese city of Hiroshima. At 8:15 a.m. local time, an atomic bomb called “Little Boy” was dropped, exploding 1,800 feet over the city and unleashing the equivalent of 20,000 tons of TNT. Approximately 80,000 people were killed as a direct result of the blast, and another 35,000 were injured. Thousands more died from radiation by the end of the war.
The use of the atomic bomb did not persuade the Japanese to surrender. Believing the use of a second atomic bomb in quick succession after the first would lead to Japan’s surrender, a second B-29 named Bock’s Car with an atomic bomb called “Fat Man” took off on August 9, 1945. Piloted by Major Charles W. Sweeney, the target was the Japanese port city of Kokura. Inside the B-29 was a bomb 40% more powerful than the bomb dropped three days earlier on Hiroshima. When the B-29 and its deadly cargo arrived over Kokura, clouds obscured the crew’s view of the city. A decision was made to proceed to the secondary target that day—the city of Nagasaki. At 11:02 a.m. local time, the bomb was dropped and exploded 1,650 feet over Nagasaki, killing 40,000 people. Five years after the bomb was dropped, the total death toll was over 100,000 due to the lingering effects of radiation.
The same day an atomic bomb was dropped over Nagasaki, the Soviet Union attacked the Japanese in Manchuria. This was finally too much for Emperor Hirohito.
As terrible as they were, the atomic bombs did have their intended effect. On August 14, 1945, Japanese Emperor Hirohito addressed the Japanese people for the first time, announcing Japan’s unconditional surrender. The deadliest and most significant conflict in human history had come to an end.
The Aftermath
Hideki Tojo was a general who served as Japan’s prime minister from 1941 to 1944. He led the Japanese military through the war and was convicted of war crimes after Japan’s surrender. The blood of millions was on Tojo’s hands, and he was executed on December 23, 1948.
News of the Japanese surrender led to celebrations across the country, with people flooding the streets of large cities like New York and Los Angeles. World War II ended formally on the deck of the battleship USS Missouri in Tokyo Bay on September 2, 1945. General Douglas MacArthur, the commander-in-chief of all U.S. forces in the Pacific, made a short address as he received the Japanese delegation. He stated, “It is my earnest hope and indeed the hope of all mankind that from this solemn occasion a better world shall emerge out of the blood and carnage of the past—a world founded upon faith and understanding—a world dedicated to the dignity of man and the fulfillment of his most cherished wish—for freedom, tolerance and justice.”
The scale of the death and suffering as a result of World War II worldwide is difficult to grasp. The low end of the worldwide death count is 50 million people, with the high end now estimated at 85 million people. Millions were injured, while millions more had their lives shattered or were displaced. It was human suffering that all people of goodwill must take every measure to ensure is never repeated.
As with Germany, the United States needed to address what to do with those in the defeated Japanese regime. Japanese military and government officials committed numerous war crimes throughout World War II. They were responsible for millions of civilian murders.
Japan did not sign the 1929 Geneva Convention on the humane treatment of prisoners of war. The Japanese military considered surrender dishonorable, so they looked at captured prisoners of war with disdain and terribly mistreated Americans in captivity in many circumstances. The fatality rate among American prisoners of war held in Japanese captivity was approximately 40%. For comparison, Americans held in German captivity had a fatality rate closer to 4%, although this number excludes Soviet prisoners of war whose rate was much higher.
The treatment of soldiers during the Bataan Death March in April 1942 in the Philippines was another example of Japanese brutality, as about 65,000 captured Filipino soldiers and 10,000 American soldiers were forced to march 65 miles to prison camps. Approximately 10,000 of these men died or were killed along the way.
In January 1946, the International Military Tribunal for the Far East (IMTFE) was created among eleven nations, including the United States, to bring Japanese war criminals to justice. Twenty-eight defendants were ultimately put on trial, most notably, Hideki Tojo. After 419 witnesses and a trial that lasted until November 1948, seven defendants were sentenced to death, including Tojo, and 16 were given life sentences.
Much like the Nuremberg trials in Germany against high-ranking Germans responsible for the Holocaust and other atrocities, the trials in Tokyo against the Japanese military and government officials left many undeservedly free from justice. One Japanese name stands out among this group. Shiro Ishii, the evil and sadistic director of Unit 731, a secret facility that subjected humans, mainly from China, to all sorts of twisted tortures in the name of research, was never brought to justice.
Japanese at Unit 731 murdered as many as 300,000 people. Ishii faked his own death in 1945 but was later found. Fearing the rising threat posed by the Soviet Union after the war, American officials sought to prevent the Soviets from gaining the knowledge Ishii had collected about deadly pathogens and biological weapons while directing Unit 731. In exchange for sharing his research exclusively with the Americans, Ishii was given immunity from prosecution. His research ultimately proved to be of little use. If execution was the punishment for the worst human rights violators, Ishii should have been at the front of the line. Instead, he died a free man in 1959.
Emperor Hirohito
The fate of Emperor Hirohito is another aspect of the war’s conclusion that is still debated today. The American occupation of Japan was led by Gen. Douglas MacArthur and lasted until 1952. Democratic reforms were implemented, and the country was demilitarized. MacArthur believed that Hirohito should remain on the throne to stabilize Japan, although with his power limited to ceremonial duties only. He was never put on trial for war crimes, even though there is a consensus that he was, at a minimum, complicit in Imperial Japan’s actions and crimes because he was in a position to stop them, but did not. How active Hirohito was in approving Japan’s military actions and many of its war crimes is still debated; however, as a head of state, he bore a large share of responsibility. Emperor Hirohito visited Disneyland in Anaheim in 1975 and served as Emperor of Japan until he died in 1989.
On the American side, President Franklin Roosevelt issued Executive Order 9066 in February 1942, which ordered the forced relocation of up to 125,000 individuals of Japanese ancestry, American citizens and non-citizens alike, to internment camps on the West Coast of the United States. After the bombing of Pearl Harbor, Roosevelt reasoned that Japanese living in the United States could still be loyal to Japan and, therefore, were national security threats capable of acts of sabotage or espionage.
The internment camps, along with the Supreme Court’s 1944 decision upholding Roosevelt’s executive order in Korematsu v. United States, were a low point for the United States in its conduct of the war. Many Japanese-Americans bravely fought in the American military against the Japanese. In 1988, President Ronald Reagan signed a bill to give restitution to those subject to this order, commenting, “Yes, the Nation was then at war, struggling for its survival, and it’s not for us today to pass judgment upon those who may have made mistakes while engaged in that great struggle. Yet we must recognize that the internment of Japanese-Americans was just that: a mistake.”
Any American transgressions committed during the war would pale in comparison to a world where American and Allied forces were defeated. The world would be a far different place today if the governments of Nazi Germany or Imperial Japan had been allowed to continue. There would have been far more death, far more suffering, and far less freedom if this had occurred.
The war touched every American. It produced over sixteen million American veterans, and as of this writing, eighty years later, slightly more than .0025% remain alive. 405,000 American military members were killed, and tens of thousands more were wounded.
It took a commitment unlike anything else in the nation’s history, along with the sacrifice of a generation of Americans, to overcome the evil faced in both Europe and the Pacific. The freedoms we enjoy today are due to the men and women of the generation often referred to as the Greatest Generation. For them, we are eternally grateful.
The work did not stop after the war’s conclusion, as the United States played a significant role in rebuilding Japan and Germany and helping the millions of people who had been displaced. Both countries became American allies in a new world, although a divided Germany became a flashpoint in the subsequent Cold War with the Soviet Union.
World War II started the nuclear age, an aspect of the war that will be with us forever. This left those at the forefront of creating this technology conflicted, especially Robert Oppenheimer. He stated, “If atomic bombs are to be added as new weapons to the arsenals of a warring world, or to the arsenals of nations preparing for war, then the time will come when mankind will curse the names of Los Alamos and Hiroshima. The people must unite or they will perish.”
While wars continued throughout the twentieth century and to this day, no nuclear powers have gone to war against each other. The bombings of Hiroshima and Nagasaki showed us the awful consequences of using these weapons ever again.
It was Dwight D. Eisenhower, the Supreme Allied Commander in Europe, who best summarized his feelings about war. In January 1946, he stated, “I hate war as only a soldier who has lived it can, only as one who has seen its brutality, its futility, its stupidity.”
Please Read:
Fighting Imperial Japan: America Strikes Back at Midway
Fighting Imperial Japan: The Flags of Iwo Jima
Please Visit:
The National World War II Museum
https://www.nationalww2museum.org/