On Aug. 6, 1945, 8 year-old Shigeaki Mori was walking across a bridge on his way to summer classes when “suddenly, I felt a massive shock wave and a blast from above,” he recalled recently. That blast, which obliterated Mori’s hometown of Hiroshima, Japan, was caused by the world’s first-ever nuclear attack.
Mori was blown off the bridge and into a shallow river. When he regained consciousness, nearly everything around him was enveloped in thick black smoke, and the few things Mori could see, like a woman walking toward him, were horrifying.
“She was swaying...and holding something white,” he said. “I realized she was holding the contents of her stomach.”
The United States dropped an atomic bomb on Hiroshima-and three days later on the Japanese city of Nagasaki-70 years ago to force Japan to surrender and end WWII (1935-1945). The bombings killed as many as 250,000 and led to Japan’s official surrender three weeks later, which arguably saved many thousands of American lives.
But dropping those bombs also had long-lasting consequences for the US and the world that plague us today. In the years since, more nations have developed their own nuclear arsenals. Today, the threat of an attack by rogue nations like North Korea or Iran-or from a terrorist group that gets its hands on a bomb-remains a terrifying security problem for the US and the world, with no easy solution.
How did the US come to possess the most destructive weapon the world had ever known? It started with a letter that physicist Albert Einstein wrote to President Franklin D. Roosevelt on Aug. 2, 1939-a month before Nazi Germany invaded Poland and started the Second World War. Einstein, a Jew who had fled Germany in 1933, warned Roosevelt about the potential destructive power of a nuclear weapon. He urged the president to fund a project to develop an atomic bomb-and quickly, before Germany’s dictator Adolf Hitler beat him to it.
Roosevelt heeded Einstein’s warning and partnered with Britain and Canada to recruit thousands of scientists to collaborate on the Manhattan Project (so named because it began in an obscure office in New York City). Stationed at isolated sites in Tennessee, Washington State, and New Mexico beginning in 1942, the scientists worked feverishly to figure out how to unleash the enormous amounts of energy contained in atoms. Einstein had first theorized the relation between matter and energy in his 1905 equation E=mc2. Because other countries, like the Soviet Union, Germany, and Japan, were also racing to develop an atomic weapon, the Manhattan Project was kept top secret.
Roosevelt never got to see the project’s completion. He died on April 12, 1945. Shortly after, Secretary of War Henry Stimson sent President Harry S. Truman a brief memo referring to “a highly secret matter” that “has such a bearing on our present foreign relations...that I think you ought to know about it without much further delay.” 3 (Truman had become vice president in January 1945, but Roosevelt had never told him about the Manhattan Project.)
The first test to see whether the bomb worked took place on July 16, 1945, with scientists and military experts gathering at Alamogordo, New Mexico. Just before dawn, a giant fireball exploded into a mass of dust and gaseous iron, soaring a mile a minute and forming a mushroom cloud. The blast carved a 1,200-foot crater in the desert floor. The blinding light and enormous roar traveled hundreds of miles.
The atom bomb came too late to affect the war in Europe, where more than 300,000 American soldiers had died; Germany had already surrendered in May. But fighting still raged in the Pacific, and Japan-which drew the US into WWII by attacking Pearl Harbor in Hawaii on Dec. 7, 1941-showed no signs of giving up. Dropping the atomic bomb as opposed to committing US troops to an invasion of mainland Japan would save half a million lives, Truman said. America’s use of the atom bomb-to this day, the only time it was ever used-is still controversial.
“The Americans had concluded that the Japanese, [with] their kamikaze suicide attacks and their refusal to surrender-you couldn’t fight people like that with anything but full measures,” says Christopher Hamner, a history professor at George Mason University in Fairfax, Virginia.
On August 6, an atomic bomb-named Little Boy by one of the nuclear physicists-was dropped on Hiroshima, a city of several hundred thousand people in southern Japan. Nearly 70 percent of the city’s buildings and houses were leveled or irreparably damaged. The War Department (today the Defense Department) said the bomb packed more explosive power than 20,000 tons of TNT.
Three days later, a second bomb, called Fat Man, was dropped on Nagasaki, about 200 miles southwest. The two bombs killed between 150,000 and 250,000 people-some immediately and some from radiation sickness later on.
On August 15, Japan accepted the Allies’ peace terms, and on September 2, it formally surrendered, finally ending World War II.
The Cold War
After the war, America found itself embroiled in a new conflict that would last five decades: the Cold War with Communist Soviet Union, which had been an ally in the fight against Nazi Germany in WWII. The US assumed it would have the upper hand in this battle because it was the only country in the world with atomic weapons. But America’s nuclear monopoly abruptly ended in September 1949, when it became clear that the Soviets had developed their own bomb, helped in part by information from American spies Ethel and Julius Rosenberg.
The nuclear arms race between the US and the soviets was fierce. The irony was that both sides were extremely hesitant to use any of their bombs: They realized an attack from either side would result in immediate retaliation. That belief became known as “mutual assured destruction” (or the appropriately named acronym MAD). In schools across the US, students participated in “duck and cover” drills, practicing huddling under their desks in case of an attack. (Never mind that ducking under a desk in the face of a nuclear attack is pretty useless.) And the Cold War almost turned hot in 1962 with the Cuban Missile Crisis, which brought the US and Soviets to the brink of nuclear war.
To reduce the chances of a nuclear war Armageddon, dozens of countries signed the United Nations’ 1968 Non-Proliferation Treaty. And in the decades leading up to the Soviet Union’s collapse in 1991, the Soviets and the US signed several treaties to reduce their respective nuclear arsenals. (In recent years, the US and Russia, which controls the old Soviet arsenal, have further reduced their stockpiles.)
Despite these efforts, the nuclear threat remains. Today, at least nine countries, including the US, have the bomb. And Iran is suspected of being close to developing nuclear weapons, posing a serious threat to Israel and Saudi Arabia-both longtime US allies in the region-and most of Europe. The US and its allies have imposed economic sanctions on Iran and have tried negotiating with its leaders to end its nuclear program, so far without success.
North Korea, which joined the nuclear club in 2006, is now led by the mysterious and unpredictable Kim Jong-Un. There’s fear that he’ll use his nuclear weapons to attack South Korea or Japan, or sell them to terrorist groups like Al Qaeda or ISIS, which could target the US. Speaking at a nuclear-security summit in Belgium last year, President Obama said one of his biggest concerns is “the prospect of a nuclear weapon going off in Manhattan.” The massive destruction that one terrorist could unleash-even without a military force behind him-is perhaps the most frightening legacy of the creation of the atom bomb.
“[Before 1945], if you wanted to do that kind of damage, you had to field an army of 75,000 men,” says Hamner, the history professor. “Today, a very determined small group of people can do an incredibly disproportionate amount of damage. THE ATOMIC AGE TIMELINE
1905 E=mc2 Albert Einstein publishes modern science’s most famous equation. It says that vast amounts of energy can be unleashed from tiny amounts of matter. It’s the basis for the development of nuclear weapons.
1942 The Manhattan Project Thousands of scientists are recruited to work on a top-secret effort to develop an atomic bomb for the US during WWII. Three years later, they successfully test the bomb in the New Mexico desert July 16, 1945.
1945 Hiroshima and Nagasaki
1949 A US spy plane learns that the Soviet Union has tested an atomic bomb. Schools begin conducting “duck and cover” drills in US schools in case of a Soviet nuclear attack.
1951 Homegrown Spies Americans Julius and Ethel Rosenberg are convicted of conspiring to steal designs for America’s atomic bomb and deliver them to the Soviet Union. They are executed two years later.
1962 Cuban Missile Crisis US spy planes discover Soviet-built nuclear missile sites in Cuba just 90 miles from Florida. After a tense 13-day standoff with the US, the Soviets agree to remove the missiles.
1968 UN Treaty The UN approves the Non-Proliferation Treaty to halt the spread of nuclear arms. Nuclear nations agree to help other countries use the technology for peaceful purposes, like electricity. The treaty has been signed by 189 countries.
1969 SALT The Strategic Arms Limitations Treaty (SALT) between the US and the Soviet Union in 1969 is the first of several agreements over the next two decades to reduce nuclear arsenals.
2010 New Start President Obama, who vowed to make nuclear disarmament an administration priority, signs a major arms-reduction agreement, with Russia, called New Start. Obama has since pushed for further reductions, but Russian President Vladimir Putin has resisted.
Today North Korea & Iran The US fears North Korea could sell arms to terrorists who could target the US. The US and its allies have imposed economic sanctions on Iran to curb its suspected nuclear weapon program; ongoing talks with Iran have so far yielded no progress. As of 4/1/15 all parties were negotiating a deal.
THE NUCLEAR CLUB: Who’s got nukes, and when did they get them?
Estimated Warheads Today
1 "New York Times Upfront - The New York Times." 2007. 30 Mar. 2015 <http://www.nytimes.com/learning/teachers/upfront/index.html>
2 "Letter from Albert Einstein to FDR, 8/2/39 . Truman . WGBH ..." 2011. 30 Mar. 2015 <http://www.pbs.org/wgbh/americanexperience/features/primary-resources/truman-ein39/>
3 "Letter Henry Stimson to Truman . Truman . WGBH American ..." 2011. 30 Mar. 2015 <http://www.pbs.org/wgbh/americanexperience/features/primary-resources/truman-stimson/>