Explain the reasons for the dropping of atom bombs on Japan and its short and long-term effects.

Nuclear weapon test Romeo, Bikini Atoll, 1954
Nuclear weapon test Romeo, Bikini Atoll, 1954

Topics on this page include

Background for the Atomic Bomb
The Bombing of Japanese Cities
Aftereffects and Reactions
Political and Social Impacts
Continuing Nuclear Tests
Women's History of the Atomic Era
Lesson Plans

Focus Question: What were the reasons for and impacts of the dropping of atom bombs on Japan?

Screen Shot 2016-02-27 at 11.29.04 AM.pngAlperovitz, Gar. The Decision To Use the Atomic Bomb and the Architecture of an American Myth, (New York: Alfred A. Knopf, 1995).

The Race to Build--and Steal--The World's Most Dangerous Weapon. Steve Sheinkin, 2013

rotating gif.gifFor more on this topic

Background for the Atomic Bomb

primary_sources.PNGClick here for video of Robert Oppenheimer's "I am become Death" speech after the detonation of the atom bomb in the deserts of New Mexico.

Multimedia.pngClick here for a video of The World's Biggest Bomb America's and the Soviet's race to see who could build and detonate the first atomic bomb.

game_icon.svg.pngSee Ground Zero for a visualization of the effects of various atomic weapons on a geographical area using Google maps. The site includes historical information about when different atomic bombs were first used.

external image img3125.jpg

Overview of the Atomic Bombing of Japanese Cities

Between 1930 and 1945, more than $2 billion was spent by the US government on the “Manhattan Project,” an effort to build an atomic bomb.

During WWII, Japan was known for its fierce fighting style. Japan's policies of mass suicide and kamikaze attacks displayed to the rest of the world that it would stop at nothing to win. But the Allies instituted extreme forms of warfare as well.
  • In 1945, as part of the Allies' Strategic Bombing campaigns which targeted the civilian populations of enemy nations, the United States firebombed the Japanese capital city Tokyo, killing over 100,000 people, but Japan did not surrender.

  • On August 6, 1945, the United States dropped a uranium bomb called “Little Boy” on the city of Hiroshima. In an instant, 66,000 people were killed and 69,000 were injured by the 10-kiloton atomic explosion, including men, women and children, both military and civilian.

  • The radius of the impact was two and a half miles, and everything within that radius burned. Of 76,000 buildings near the epicenter of the explosion, 70,000 were flattened, and 140,000 of the city’s 400,000 inhabitants died by the end of 1945. Over the next five years, another 50,000 perished from the lingering effects of radiation.

external image Japan_map_hiroshima_nagasaki.png
  • On August 9, three days after the attack on Hiroshima, the United States dropped a second atomic bomb, a plutonium bomb called “Fat Man,” on the city of Nagasaki. Though it missed its target by over a mile and a half, the bomb killed 39,000 people in Nagasaki and injured more than 25,000.

  • On August 15, 1945 Japan announced its surrender to the Allies, signing the Instrument of Surrender on September 2, officially ending World War II.

The long-term effects of the bombings of Hiroshima and Nagasaki were both physical and political.

Rotating_globe-small.gifCheck out this link with a timetable of the events leading up to and following from the dropping of the bombs on Hiroshima and Nagasaki.


Aftereffects and Reactions

Hiroshima Peace Bell
Hiroshima Peace Bell

Rotating_globe-small.gifGround Zero 1945: Pictures by Atomic Bomb Survivors
Multimedia.pngHere is an interactive 360 degree panoramic view of Hiroshima after the atomic blast

After an atomic bomb explodes, ‘fallout’ follows, including rain containing radioactive particles. This rain caused radiation poisoning and killed people in the two cities who had survived the actual explosions. Also, long-term effects of radiation include many cancers, such as leukemia, which is passed down in the families of survivors.

  • Infrastructure is also affected by atomic weapons. A large enough explosion can send out serious enough EMP (Electro-Magnetic Pulse) waves to scramble all electronic devices within a 50-mile radius.
  • While it was once thought that atomic explosions would aid in mining and canal building, the destruction of Hiroshima and Nagasaki ended any pursuit of practical applications for atomic bombs outside of the military sphere.

Click on the link Tales of Two Cities to learn how the atomic bomb destroyed the people and cities of Hiroshima and Nagasaki, Japan.

Primary Source- letters written against the Atomic Bomb

Hear a speech from Albert Einstein and his view of the bomb: Albert Einstein and the Nuclear Bomb

Political and Social Impacts

There was immediate international protest after the US dropped the bombs on Japan, with pictures of the devastation traveling around the world. Later, scientists involved in the development of the atomic bomb shared how they had tried to prevent its use against people, and reflected on the differences that might have made in world politics.
primary_sources.PNGIn an August 15, 1960, interview with U.S. News and World Report, Dr. Leo Szilard described his efforts to reach President Roosevelt, and then President Truman, to urge against actually using the bomb—even though Dr. Szilard had originally advocated for its creation. Click here for more documents on the atomic bombings .

The threat of even worse devastation—nuclear weapons technology and power grew steadily through the 1980s—helped perpetuate the idea of “Mutually Assured Destruction” throughout the Cold War between the USSR and the US.

primary_sources.PNG "Human memory has a tendency to slip, and critical judgment to fade, with the years and with changes in lifestyle and circumstance. But the camera, just as it seized the grim realities of that time, brings the stark facts … before our eyes without the need for the slightest embellishment. Today, with the remarkable recovery made by both Nagasaki and Hiroshima, it may be difficult to recall the past, but these photographs will continue to provide us with an unwavering testimony to the realities of that time."
--Yosuke Yamahata, photographer who documented the devastation the day after the bomb fell near Nagasaki.

Rotating_globe-small.gifThis link goes into detail about the effects of the atomic bomb on Japan and its people.

Rotating_globe-small.gifFor more on this topic, see Children of the Atomic Bomb: A UCLA Physician's Eyewitness Report and Call to Save the World's Children.

Sadako Statute
Sadako Statute

book.pngSadako and the Thousand Paper Cranes

  • A story about a young girl who discovers she has leukemia some years after surviving the atomic bomb blast. In the spirit of an ancient Japanese legend, she tries to make 1000 paper cranes in order to be granted the wish of health.
      • This link looks at the impact of the use of atomic warfare on the Japanese and on how the community came together after the death of a young girl named Sadako

The Girl Who Transformed the Paper Crane into the Symbol for Peace and Hope

Paper Cranes and the Children's Peace Monument

Continuing Nuclear Testing by the United States

Maps courtesy of www.theodora.com/maps used with permission

Rotating_globe-small.gifIn the 1950s, the US tested atomic bombs of greater and greater intensity out in the Pacific Ocean, at sites such as Bikini Atoll in the Marshall Islands.
From June 30, 1946, to August 18, 1958, the United States conducted 67 nuclear tests in the Marshall Islands, all of which were considered atmospheric. The most powerful of those tests was the "Bravo" shot, a 15 megaton device detonated on March 1, 1954, at Bikini atoll. That test alone was equivalent to 1,000 Hiroshima bombs.[1] Below is a document containing testimony from the UN International Court of Justice tribunal on Nuclear Testing in the Marshall Islands.

primary_sources.PNGSuch testing was common until the Nuclear Test Ban Treaty was signed. Find the full document here. More information about the Nuclear Test Ban Treaty can be found here: from the John F. Kennedy Presidential Library and Museum.

Female_Rose.pngWomen's History of the Atomic Bomb Era

Click here for a video "Women Speak Out For Peace: Testimonies of Hiroshima and Nagasaki".

external image 200px-Paperback_book_black_gal.svg.pngThe Girls of Atomic City: The Untold Story of Women Who Helped Win World War II. Denise Kiernan, 2013.

Click below to read about women who worked as scientists on the Manhattan Project.

Minorities against the Nuclear Bomb- the site below links to a prominent book on African American's who protested the making of the Atomic bomb.

Lesson Plans for Teachers and Students

external image Red_apple.jpg "Victory in the Pacific:1943-1945": Lesson Plan from the National Endowment for the Humanities

A multimedia-inclusive and critical thinking lesson titled "An Atomic Dilemma" from a New York Times article in conjunction with The Learning Company can be found here, and includes numerous further resources for supplemental study. This resource comes from the Teaching History page "August 1945: Hiroshima and Nagasaki", a sort of clearinghouse of informational links, found here. Note: check the links throughout the article, some of them are inactive or broken now.

This link is a great resource that provides information followed by questions for students to answer based on the readings.

Possible discussion questions for students
  • If citizens are supporting their army’s fighting by building weapons and other military supplies, are they civilians? What if they are forced to do this labor?
  • Why did the US drop the A-bomb on Japanese cities and not on any cities in Germany or Italy?
  • What effect might the publicity of the bombings’ aftermath have had on the Cold War and the policy of Mutually Assured Destruction?
  • How does learning about another country’s perceptions of a war change your view of that war? How does it change your view of history as a subject?


[1] African Americans against the Bomb by Victor Intondi

[2]https://www.atomicheritage.org/history/women-and-bomb women and the making of the bomb

[3] documents on the decision whether to drop the bombs

[4] Hiroshima Peace Memorial Museum http://www.pcf.city.hiroshima.jp/virtual/VirtualMuseum_e/tour_e/tour_fra_e.html
An interesting web site, for history, real experiences of people who experienced the devastation of Hiroshima in 1948—and also as a look at point of view; not propaganda as much as how a nation sees history in different ways than we do in the US.

[5] http://www.pcf.city.hiroshima.jp/virtual/VirtualMuseum_e/exhibit_e/exhi_fra_e.html
Link to special exhibit at the museum about foreign reporting and aid after the bomb was dropped.

[6] http://www.peak.org/~danneng/decision/usnews.html
US News and World Report interview on decision with Leo Szilard

[7] www.exploratorium.edu/nagasaki/mainn.html
web site for San Francisco's science museum The Exploratorium;
Exhibit: Remembering Nagasaki, The Photographs of Yosuke Yamahata

[8] http://www.mphpa.org/classic/LC/decision_to_drop.htm
This site provides reasoning behind choices to use the atomic bomb and for Japanese surrender to end WWII

[9] https://www.youtube.com/watch?v=U7o5MDOjVYw

Previously cited sources

  1. Duiker, William J. and Spielvogel, Jackson J., (2005). The essential world history. Belmonet, CA: Wadsworth, a division of Thomson Learning, Inc.
  2. Kelly, Martin (2007). American History. Retrieved March 7, 2007, from About Web site: http://americanhistory.about.com/od/worldwarii/a/presshiroshima_2.htm
  3. [first link in revised text re: theories on reasons why] Lewis, Chris H. (2002). Did the US need to drop the atomic bomb on Japan in order to end World War 2?. Retrieved March 26, 2007, from American studies 2010 Web site: http://www.colorado.edu/AmStudies/lewis/2010/atomic.htm
  4. Burr, WIlliam (2005, Aug 5). The Atomic Bomb and The End of World War 2. Retrieved March 7, 2007, from The National Security Archive Web site: http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB162/index.htm
  5. Otherground, LLC.,, (2003). World War 2. Retrieved March 7, 2007, from World War 2 Atomic Bomb Web site: http://www.world-war-2.info/atomic-bomb/
  6. The New York Times Company, (2007). The history of atomic bomb. Retrieved March 25, 2007, from About: inventors Web site: 5. http://inventors.about.com/library/weekly/aa050300a.htm

More sites of interest

City of Hiroshima's web site

Also from Exploratorium site—responses to questions on how person first learned of the bombings and their impressions of them. Part of project on nature of memory.
  1. ^ "U.S. Nuclear Testing Program in the Marshall Islands", http://www.nuclearclaimstribunal.com/testing.htm, Retrieved February 28, 2011.