Revisiting Hiroshima in Iran: Real American Attitudes about Dropping the Bomb
Abstract: Numerous polls show that U.S. public approval of Truman’s decision to drop atomic bombs on Hiroshima and Nagasaki has declined significantly since 1945. Scholars and pundits have suggested that this is a sign of the emergence of a “nuclear taboo.” Such polls, however, do not force respondents to contemplate the tradeoff the U.S. government believed it faced in 1945: choosing between the use of nuclear weapons and a ground invasion of Japan to end the Pacific War. This paper reports on survey experiments recreating that kind of a tradeoff in a hypothetical war with Iran. In order to avoid a ground assault on Tehran that was predicted to kill 20,000 American soldiers, 60% of the U.S. public approved of an atomic attack on an Iranian city that would kill 100,000 civilians and 60% approved of an atomic attack that would kill 2,000,000 civilians. Sixty-seven percent preferred a conventional bombing attack that was estimated to kill 100,000 Iranian civilians. Moreover, the prospect of killing more noncombatants appeared to trigger beliefs in retribution and complicity, as a way of justifying the decisions. Our findings suggest that U.S. public support for the principle of noncombatant immunity is shallow.
About the Speaker: Scott D. Sagan is the Caroline S.G. Munro Professor of Political Science, the Mimi and Peter Haas University Fellow in Undergraduate Education, and Senior Fellow at the Center for International Security and Cooperation and the Freeman Spogli Institute at Stanford University. He also serves as Project Chair for the American Academy of Arts and Sciences’ Initiative on New Dilemmas in Ethics, Technology, and War and as Senior Advisor for the American Academy of Arts and Sciences’ Global Nuclear Future Initiative. Before joining the Stanford faculty, Sagan was a lecturer in the Department of Government at Harvard University. From 1984 to 1985, he served as special assistant to the director of the Organization of the Joint Chiefs of Staff in the Pentagon. Sagan has also served as a consultant to the office of the Secretary of Defense and at the Sandia National Laboratory and the Los Alamos National Laboratory.
Sagan is the author of Moving Targets: Nuclear Strategy and National Security (Princeton University Press, 1989); The Limits of Safety: Organizations, Accidents, and Nuclear Weapons (Princeton University Press, 1993); and, with co-author Kenneth N. Waltz, The Spread of Nuclear Weapons: An Enduring Debate (W.W. Norton, 2012). He is the co-editor of Planning the Unthinkable (Cornell University Press, 2000) with Peter R. Lavoy and James L. Wirtz; the editor of Inside Nuclear South Asia (Stanford University Press, 2009); and co-editor of a two-volume special issue of Daedalus, On the Global Nuclear Future (Fall 2009 and Winter 2010), with Steven E. Miller. Sagan’s recent publications include “A Call for Global Nuclear Disarmament” in Nature (July 2012); “Atomic Aversion: Experimental Evidence on Taboos, Traditions, and the Non-Use of Nuclear Weapons” with Daryl G. Press and Benjamin A. Valentino in the American Political Science Review (February 2013); and, with Matthew Bunn, the American Academy of Arts and Sciences occasional paper, “A Worst Practices Guide to Insider Threats: Lessons from Past Mistakes” (2014).
Sagan was the recipient of the National Academy of Sciences William and Katherine Estes Award in 2015 and the International Studies Association's International Security Studies Section Distinguished Scholar Award in 2013. He has also won four teaching awards: Stanford’s 1998-99 Dean’s Award for Distinguished Teaching; Stanford's 1996 Hoagland Prize for Undergraduate Teaching; the International Studies Association’s 2008 Innovative Teaching Award; and the Monterey Institute for International Studies’ Nonproliferation Education Award in 2009.
Scott D. Sagan
CISAC
Stanford University
Encina Hall, E202
Stanford, CA 94305-6165
Scott D. Sagan is Co-Director and Senior Fellow at the Center for International Security and Cooperation, the Caroline S.G. Munro Professor of Political Science, and the Bass University Fellow in Undergraduate Education at Stanford University. He also serves as Co-Chair of the American Academy of Arts and Sciences’ Committee on International Security Studies. Before joining the Stanford faculty, Sagan was a lecturer in the Department of Government at Harvard University and served as special assistant to the director of the Organization of the Joint Chiefs of Staff in the Pentagon.
Sagan is the author of Moving Targets: Nuclear Strategy and National Security (Princeton University Press, 1989); The Limits of Safety: Organizations, Accidents, and Nuclear Weapons (Princeton University Press, 1993); and, with co-author Kenneth N. Waltz, The Spread of Nuclear Weapons: An Enduring Debate (W.W. Norton, 2012). He is the co-editor of Insider Threats (Cornell University Press, 2017) with Matthew Bunn; and co-editor of The Fragile Balance of Terror (Cornell University Press, 2022) with Vipin Narang. Sagan was also the guest editor of a two-volume special issue of Daedalus: Ethics, Technology, and War (Fall 2016) and The Changing Rules of War (Winter 2017).
Recent publications include “Creeds and Contestation: How US Nuclear and Legal Doctrine Influence Each Other,” with Janina Dill, in a special issue of Security Studies (December 2025); “Kettles of Hawks: Public Opinion on the Nuclear Taboo and Noncombatant Immunity in the United States, United Kingdom, France, and Israel”, with Janina Dill and Benjamin A. Valentino in Security Studies (February 2022); “The Rule of Law and the Role of Strategy in U.S. Nuclear Doctrine” with Allen S. Weiner in International Security (Spring 2021); “Does the Noncombatant Immunity Norm Have Stopping Power?” with Benjamin A. Valentino in International Security (Fall 2020); and “Just War and Unjust Soldiers: American Public Opinion on the Moral Equality of Combatants” and “On Reciprocity, Revenge, and Replication: A Rejoinder to Walzer, McMahan, and Keohane” with Benjamin A. Valentino in Ethics & International Affairs (Winter 2019).
In 2022, Sagan was awarded Thérèse Delpech Memorial Award from the Carnegie Endowment for International Peace at their International Nuclear Policy Conference. In 2017, he received the International Studies Association’s Susan Strange Award which recognizes the scholar whose “singular intellect, assertiveness, and insight most challenge conventional wisdom and intellectual and organizational complacency" in the international studies community. Sagan was also the recipient of the National Academy of Sciences William and Katherine Estes Award in 2015, for his work addressing the risks of nuclear weapons and the causes of nuclear proliferation. The award, which is granted triennially, recognizes “research in any field of cognitive or behavioral science that advances understanding of issues relating to the risk of nuclear war.” In 2013, Sagan received the International Studies Association's International Security Studies Section Distinguished Scholar Award. He has also won four teaching awards: Stanford’s 1998-99 Dean’s Award for Distinguished Teaching; Stanford's 1996 Hoagland Prize for Undergraduate Teaching; the International Studies Association’s 2008 Innovative Teaching Award; and the Monterey Institute for International Studies’ Nonproliferation Education Award in 2009.
