Analysis & Opinions - Belfer Center for Science and International Affairs, Harvard Kennedy School

Center Experts Reflect on 75th Anniversary of Hiroshima Bombing

The bombing of Hiroshima, Japan, on August 6, 1945, announced the dawn of the nuclear age. The world has been living with the dangers of nuclear weapons since that day 75 years ago. Below, several Belfer Center experts offer their reflections on this somber occasion.

Expert comments:

GRAHAM ALLISON, Douglas Dillon Professor of Government

“After the U.S. dropped atomic bombs on Hiroshima and Nagasaki in August 1945 to force Japan to surrender in World War II, if anyone had suggested that for the next three quarters of a century, no nuclear weapon would again be used in war, he would have been ridiculed. 'Unimaginable,' pundits would have declared. That this has occurred is not only reason to give thanks, but grounds for believing that human beings can learn!

In the past seven  and a half decades, the world has seen several close calls, most dangerously in the Cuban Missile Crisis of 1962. Over time, however, nuclear superpowers came to understand that neither could kill its adversary without destroying itself. This brute fact forced rational governments to accept constraints on their competition that would historically have been unacceptable. As Ronald Reagan put it famously in a favorite one-liner: A nuclear war cannot be won, and must therefore never be fought. 

This remains a central constraint in relations between the U.S. and what Washington calls its two 'great power rivals:' China and Russia. However unacceptable their behavior, however demonic either seems or even may be, a full-scale war with either could literally erase the U.S. from the map. After so many years without use of this absolute weapon in war, the possibility of nuclear Armageddon has become unimaginable for many today. It is precisely because serious constraints on geopolitical competition are  unnatural that each generation must internalize the lessons of the nuclear age.”

MATTHEW BUNN, James R. Schlesinger Professor of the Practice of Energy, National Security, and Foreign Policy

“Seventy-five years ago, a single nuclear bomb incinerated the Japanese city of Hiroshima.  Tens of thousands of men, women, and children were killed in an instant, and tens of thousands more died after terrible suffering in the days, weeks, and years to come.  Three days later, the United States dropped another nuclear bomb on Nagasaki.  Despite the terrors of the Cold War, those were the last nuclear weapons used in war; the world has managed to avoid nuclear war for 75 years, through a combination of a lot of fear, a little wisdom, and a lot of luck. Yet today, there are still thousands of nuclear weapons in the world, many poised for immediate launch.  The memory of the horrors of nuclear war should motivate us all to take action to ensure that nuclear weapons are never used in war again – and to find a path that will someday allow us to eliminate the dangers nuclear weapons pose to humanity.”

REBECCA DAVIS GIBBONSProject on Managing the Atom Associate

"Today the United States is engaged in a long-term plan to update its nuclear arsenal, spending as much as two trillion dollars over thirty years, with the new platforms expected to last through the 2080s. Despite this astounding cost and the trade-offs necessitated by spending such vast sums, there is little public discussion in the United States about nuclear policy. When polling my college students about what they know about nuclear weapons and where they learned about them, the most common source of their knowledge is video games. Few Americans know there are still over 13,000 nuclear weapons in the world, the majority of them vastly more destructive than the bombs dropped on Hiroshima or Nagasaki."

STEPHEN HERZOG, Stanton Nuclear Security Fellow, International Security Program/Project on Managing the Atom

“The bombings of Hiroshima and Nagasaki left behind a tragic legacy of death and destruction. On this 75th anniversary of the attack on Hiroshima, nine countries continue to maintain thousands of nuclear weapons. There is also a disturbing trend toward the abandonment of arms control treaties and renewed interest in nuclear weapon test explosions. It is important to reflect upon the stories of the hibakusha—survivors of the atomic bombings—and remember why these deadly weapons must be eliminated.”

SHEILA JASANOFF, Pforzheimer Professor of Science and Technology Studies

"Seventy-five years ago today the world woke to a new reality—the atomic age. The bombs dropped on Hiroshima and Nagasaki introduced new words into our vocabulary of risks to the human future: dreaded, catastrophic, apocalyptic, existential.  Soberingly, these were not risks posed by the natural world, but ones we brought upon ourselves without much forethought. Today, as we grapple with climate change and a global pandemic, and the Belfer Center looks afresh at questions of technology and public purpose, let’s stop to take stock and ask what we have learned about governing technology well since Robert Oppenheimer recalled those famous words of Vishnu, 'Now I am become Death, the destroyer of worlds.' Can we use technology to nurture and preserve worlds, not destroy them?"


JOSEPH NYE, Harvard University Distinguished Service Professor, Emeritus

“The morality of Truman’s decision has been debated since the start, but as I show in my book Do Morals Matter? people sometimes forget that Truman also created what Tom Schelling called the all important 'nuclear taboo' when he refused General MacArthur’s request to use nuclear weapons to save the situation in Korea five years later.”

For more information on this publication: Belfer Communications Office
For Academic Citation: Allison, Graham, Matthew Bunn, Rebecca Davis Gibbons, Stephen Herzog, Sheila Jasanoff and Joseph S. Nye.“Center Experts Reflect on 75th Anniversary of Hiroshima Bombing.” Belfer Center for Science and International Affairs, Harvard Kennedy School, August 6, 2020.

The Authors

Graham Allison headshot

Herzog Headshot

Joseph S. Nye, Jr.