Hiroshima and Nagasaki: War Crime or Necessary Evil?

“The force from which the sun draws its power has been loosed against those who brought war to the Far East.” With those words, US President Harry Truman announced the atomic bombing of Hiroshima. Three days later, Nagasaki was struck by a second weapon. These two strikes, delivered at the very end of the Second World War, remain among the most contested military decisions in history.

To this day they are condemned for the horrific civilian casualties they caused, and for the simple fact that they were the only wartime uses of such a weapon ever recorded. Yet many also point out that they swiftly ended the brutal Pacific theatre against an empire prepared to fight until the last man.

The question has never been fully settled, and it sits at the intersection of ethics, strategy, and historical counterfactual. Were the world’s only atomic attacks necessary in the long run, and perhaps even justified, or were they simply the first instance of the United States flexing its nuclear muscles? WarFronts takes an objective look at both sides of that debate.

Destroyer of Worlds

Early in the morning on August 6, 1945, a B-29 Superfortress nicknamed Enola Gay took off from the island of Tinian. After meeting two other bombers over Iwo Jima, it began its journey toward mainland Japan. Roughly six hours into the flight, the crew caught their first glimpse of the target: the industrial port city of Hiroshima.

Hiroshima had been selected for several reasons. It mattered as a center of manufacturing, but it was also a transport hub for the Imperial Japanese Military, making it a target with genuine strategic value alongside its dense civilian population.

As the bomber passed over the city, the payload was released. Years of work by the world’s best physicists in the top-secret Manhattan Project had led to this single moment. The atomic bomb nicknamed Little Boy, containing 64 kilograms of uranium, began plummeting toward the ground. It fell for more than 44 seconds before detonating in the air above the city.

The Scale of the Blast

Little Boy was, by any technical measure, an inefficient weapon. Less than 2 percent of its fissile material actually underwent fission. Even so, it produced the largest explosion in human history up to that point.

A blinding flash of light and a thundering boom preceded the destruction. The blast ripped through Hiroshima, annihilating almost everything within a radius of an entire mile, or 1.6 kilometers. At double that distance, intense fires raged across anything remotely flammable, and steel support beams bent from the shockwave, collapsing many buildings and damaging many more.

Even districts spared the initial explosion were not safe. A firestorm spread across much of the city, and the population was powerless to stop it. By the time the fires burned out, as much as two-thirds of Hiroshima’s infrastructure had been destroyed or severely damaged. An estimated 80,000 people were killed and another 70,000 injured. Thousands more would die in the following months as they succumbed to the high levels of radiation to which they had been exposed.

In the wake of the bombing, Truman announced the weapon’s use and declared that the Allies had spent “two billion dollars on the greatest scientific gamble in history, and won.” The Japanese Empire was again urged to accept terms of surrender, but it had no intention of doing so.

The Second Bomb and Japan’s Surrender

Three days after the first A-bomb fell, a second weapon, named Fatman, was en route, carried by a B-29 nicknamed Bockscar. This time the target was Kokura, again chosen for its military and industrial significance. When the crew arrived, however, they found the city obscured by thick smoke, the result of a nearby Allied bombing run the day before, compounded by Japanese factories burning coal tar to produce a screen of dark smoke.

Bockscar lined up three separate runs on Kokura but could never get a clear drop. By the third pass, Japanese anti-aircraft guns were getting close to hitting the plane, so the crew turned back and headed for their secondary target: Nagasaki.

When Bockscar and its weather-spotting escort appeared on Japanese radar, an air raid siren sounded throughout Nagasaki. Just 40 minutes later the all-clear was given. Seeing only two American planes overhead, observers assumed it was reconnaissance and sounded no further alarms.

Those two bombers proved as deadly as an entire army. Fatman was released minutes later. Nagasaki’s geography meant less of the city was destroyed than expected, and a crosswind blew the bomb slightly off target, but the city suffered a fate broadly similar to Hiroshima’s. Casualty estimates vary wildly, but an average figure is around 40,000 total deaths and another 60,000 injured.

Following the news of a second city devastated by an otherworldly weapon, the Japanese government accepted terms of unconditional surrender, marking the official end of the Second World War on September 2, 1945. The deadliest war in human history had been brought to a close.

Public Opinion, Then and Now

The debate over the bombings began almost immediately and has never fully cooled. A Gallup poll taken right after the war found that around 60 percent of Americans believed the use of the atom bombs was justified, a figure that has changed little in the decades since.

The numbers shift, however, when the question is phrased differently. Asked whether they approve of the use of the bombs, rather than whether the bombs were justified, Americans show a clear decline in support, from 80 percent in 1945 to only 56 percent in 2005. That gap between justification and approval helps explain why the topic remains so controversial. It is possible to believe a decision was defensible in context while still recoiling from the act itself.

A Heinous War Crime

The first perspective holds that the atom bombs were little more than two war crimes that devastated entire cities. The central argument is the immense loss of civilian life. At Hiroshima, around 20,000 of the casualties were military personnel. At Nagasaki, the number of soldiers immediately killed was only 150.

The bombs did inflict significant damage on military industry, including the destruction of the Mitsubishi Steel Works plant, but the collateral damage was immense. In downtown Hiroshima, the bomb exploded almost directly over the Shima Surgical Clinic, one of the largest hospitals in the city, wiping out medical staff in an instant.

As much as 90 percent of the city’s medical workers were killed in the blast or the resulting fires, leaving the survivors with almost no doctors to treat their injuries. Massive lines formed at the clinics that remained, and thousands died of their burns or other wounds while waiting. Most of these deaths were neither quick nor painless.

The Nature of the Dying

Near ground zero, death was effectively instantaneous, an immediate vaporizing. Further out, it was anything but. The heat was so intense that the patterns of people’s clothing were seared into their skin. Thousands were covered from head to toe in blistering burns, and thousands more suffered the effects of radiation exposure.

Radiation sickness is among the worst ways to die. Victims drift in and out of consciousness while their skin feels as if it is on fire, accompanied by intense nausea, vomiting, and diarrhea, until they eventually lose the battle to internal bleeding or infection. Those who survive the exposure are often left with permanent injuries.

The story of Tsutomu Yamaguchi captures the experience. Depending on one’s view, he was either very lucky or very unlucky: he is credited as one of the few people to survive both atomic bombings. The explosion at Hiroshima ruptured both of his eardrums, left him temporarily blind, and gave him radiation burns across his entire upper body.

Yamaguchi was less injured by the Nagasaki blast, but the radiation caused him to vomit violently for more than a week. His wounds required several years of treatment, and his daughter recalled that for the better part of a decade he was covered in bandages. Though much of his body eventually recovered, he permanently lost hearing in his left ear, and his wife suffered similar symptoms.

Yamaguchi at least had a home to return to. With most of the city destroyed or structurally unsafe, tens of thousands more were left homeless, many of them children orphaned that same day.

Was the Bomb Even Necessary?

Beyond the human cost, critics question whether the bombs were necessary at all. It is easy to draw a clean timeline in which Japan capitulated immediately after the atomic strikes, but some historians argue the empire was already contemplating surrender.

The strategic picture had collapsed. The United States had steamrolled across the Pacific and destroyed most of Japan’s navy. The Soviet Union, no longer tied up in Europe, had turned its attention eastward. After the first atom bomb fell, the Soviets invaded Japanese-occupied Manchuria and seized it within a couple of weeks.

Manchuria had been a major source of coal, iron, and wood for the empire, and losing it was a devastating blow. Perhaps not decisive on its own, but the writing was on the wall. By this reasoning, the bombs were overkill, and Japan might instead have been besieged into surrender.

A further argument concerns a possible second agenda. As the war wound down, it was already becoming clear that the Soviet Union would be America’s primary global rival, and dropping two futuristic city-killers was a powerful way to demonstrate to Moscow who held the upper hand. If that was the motive, a non-combat demonstration might have sufficed to intimidate both Japan and the Soviets, such as detonating a bomb over open Japanese fields rather than a densely populated city.

The Ends Justify the Means

The opposing view holds that the bombs were a necessary evil. It rests on the belief that, despite killing around 200,000 people, the atomic strikes ultimately saved lives.

The Pacific Front was one of the bloodiest and nastiest theatres in human history. The island combat rivaled the ferocity of the eastern front, as the United States fought to liberate territory held by Imperial Japan. One of the ugliest engagements was the Battle of Okinawa, in which more than 100,000 Imperial soldiers were killed alongside around 50,000 Americans.

The most horrifying aspect of Okinawa was the mass civilian suicide that occurred as Allied victory neared. Imperial propaganda had been working overtime for years, convincing civilians that the Americans were “white devils” intent on a rampage of raping, torturing, and slaughtering, a picture drawn to resemble what Japan itself had done when it conquered Nanjing.

The fear was so intense that thousands of fathers killed their families before taking their own lives, and waves of people threw themselves off the cliffs at the southern end of the island. Not all of these deaths were voluntary, as Japanese soldiers coerced many into the act. The Allies had no intention of treating civilians this way, but in an era long before the internet, civilians knew only what their government told them.

Operation Downfall and the Glorious Death of 100 Million

With the Japanese navy annihilated and the mainland all that remained, the Allies drafted plans to defeat the final Axis power. The result was Operation Downfall, a multi-nation amphibious assault designed to use the full force of the Allies to reach and capture Tokyo. After the experience at Okinawa and similar islands, there were grave fears that a conventional invasion would provoke the same civilian reaction on a far larger scale, and those fears were not unfounded.

The Japanese government knew its time was running out. It understood it could not win, especially after Germany had been knocked out of the fight. Its plan instead was to make any invasion seem so unbelievably costly that the Allies would prefer to negotiate a treaty.

The centerpiece was the defense of Japan, codenamed Operation Ketsugo. The plan committed the entire population to resistance, including roughly 28 million men and women in civilian militias, while conscripting any able-bodied person into the weapons factories. Thousands of kamikazes were readied in aircraft, boats, and even submarines, and any boy capable of holding a gun would be trained to use it.

There were not enough guns for everyone, so many were told to use knives, bamboo sticks, or makeshift bombs and simply hurl themselves at the Americans, instructions that extended even to children. This vision of total war was packaged in a propaganda campaign called “The Glorious Death of 100 Million,” implying it would be better for all of Japan to be wiped out than to surrender.

The Invasion That Never Came

British intelligence had picked up much of this, so the Allies knew what to expect. Operation Downfall was anticipated to be one of the bloodiest operations of the entire war, with more than a million American casualties forecast. Japanese casualties could not be predicted with precision, but estimates easily overshot 20 to 30 million.

Bracing for the slaughter, the American military began producing hundreds of thousands of Purple Heart medals to award the killed and wounded. The stockpile readied for an invasion that never happened was so large that it covered all recipients in the wars in Korea, Vietnam, Afghanistan, and Iraq, with many to spare.

The glorious death of 100 million and the world’s largest amphibious invasion never took place. The atom bombs were the deciding factor in Japan’s surrender. Viewed through this lens, the loss of 200,000 lives in the world’s only wartime use of nuclear weapons potentially saved tens of millions.

The relief was captured by a 21-year-old American preparing for Operation Downfall: “When the bombs dropped and news began to circulate that [the invasion] would not, after all, take place, that we would not be obliged to run up the beaches near Tokyo assault-firing while being mortared and shelled, for all the fake manliness of our facades we cried with relief and joy. We were going to live. We were going to grow up to adulthood after all.”

A Debate Without a Verdict

We can never know for certain whether dropping the atom bombs truly saved lives in the long run, or whether Japan would have surrendered regardless. Nor can we know whether the Glorious Death of 100 Million would have unfolded as catastrophically as its planners promised.

It is easy to criticize the decisions of the past from a modern vantage point, but doing so often yields little more than speculation. The past cannot be changed; it can only be studied. The world has come to the brink of nuclear Armageddon on more than one occasion since 1945, and has always managed, so far, to step back.

If tensions between global powers continue to rise in the coming years, the horrors that atomic weapons inflicted on Japan more than 80 years ago remain a warning worth remembering, and a reason to hope that no third city is ever added to the fateful list shared by Hiroshima and Nagasaki.