The world's first operational atomic bomb was dropped above the Japanese city
of Hiroshima at 8:15 on the morning of the 6th of August 1945.
It was carried to its target by the
USAA B-29 bomber Enola Gay,
flying from the American airbase on the Pacific island of Tinian.
Nicknamed 'Little Boy', the bomb exploded with the equivalent force of over 12
kilotons of TNT. Around 5 square miles of the city was
reduced to ashes with over 60% of the total building stock destroyed
Within four days of the blast some 120,000 civilian inhabitants had died
many of them having been instantly vaporized by the explosion
Three days later at around 11a.m on the 9th of august
another B-29 bomber from the Tinian airbase dropped the second operational
atomic bomb on the city of Nagasaki. This one was nicknamed 'Fat man' and had a
similar impact to the Hiroshima bomb - approximately 2.5 square miles of the
city were laid waste and over 70,000 people were killed as an
immediate result of the blast.
What had led to the fateful decision to
deploy these new weapons of mass destruction?
So the war in Europe had ended in may 1945 with the death of Adolf Hitler in
the Berlin bunker and the subsequent unconditional
surrender of Germany and her remaining European Allies.
This had been made possible by the Normandy landings of June 1944
and the ensuing campaign to push German forces back to the Rhine and beyond
Combined with the unstoppable advance of the red army on the eastern front
this effectively crushed the German forces between two gigantic Allied steamrollers.
But the war in the far east against Japan continued.
Considerable American, British and Commonwealth land, naval and air forces
were committed to a war of attrition over a vast area.
Japanese forces fought with fanaticism and with little regard for casualties on
either side.
Before the advent of the atomic bomb in
July 1945, the US and Allies were
planning for a conventional military defeat of Japan
as they had done previously for Germany with Operation Overlord.
The equivalent plan for the Far East was called Operation Downfall.
Downfall was designed to overrun the Japanese home islands
and bring about the desired unconditional surrender.
Planners envisaged that their forces would not be ready to begin the
operation until November 1945 and they were
expecting the whole campaign to last well into the spring of 1946.
Had it taken place Downfall would have been the largest military operation of
its kind in history, putting even overlord into the shade
But likely American and Allied
casualties were a major concern for the planners
and the American government. It was assumed that downfall would inevitably
cost the invaders very dearly in this regard
estimates vary widely worst case scenarios predicting
several million American casualties in dead and wounded
Another key concern was the possible impact on the substantial allied
prisoner of war population in Japanese hands.
Some 100,000 Allied personnel were in POW camps towards the end of the war
and it was feared that in the event of
an invasion they would all be massacred by their captors
Orders issued previously to POW camp commanders seemed to suggest that in the
event of an invasion they would be killed to prevent any
possible uprisings.
A smaller scale preview of what Downfall might look like was provided by the
Battle for Okinawa during April to June 1945.
Just over 300 miles from the Japanese mainland this large island was a vital
staging pose for any invasion force, particularly as a forward air base
The Japanese defense was mainly concentrated inland
away from the immediate invasion areas, but the Americans were immediately hit
by massed kamikaze attacks which inflicted heavy casualties amongst
the naval forces, and that was even before the marines and
infantry came up against the strongly defended Japanese positions further
inland. The projected cost of Operation Downfall
particularly in terms of allied casualties
as well as the experience of the bloody and bitter fighting for Okinawa,
combined to increase the desire for an alternative war-winning strategy.
So with what seemed like providential timing, the successful testing of the
world's first atomic bomb in the desert of New Mexico on the 16th July 1945
offered just such a solution.
This had been the result of several years of American-led research and development
codenamed the Manhattan Project, partly motivated by the need to respond to Nazi
Germany's own wartime atomic bomb project,
although this was later known to have been
much less further developed than the Americans had assumed.
From the outset Japan had also been a potential target for this new type of
bomb and the Allied leaders now had little
hesitation in acting accordingly. The declaration they issued at the
conclusion the Potsdam Conference threatened Japan with 'prompt and utter
destruction' if she did not accept unconditional surrender.
Her military hardliners blocked any moves in this direction and the decision
to deploy the Atomic bomb was made
Hiroshima was selected as the first target as it was an important economic
and military hub that had so far escaped serious air raid damage
When the Japanese surrender was still
not forthcoming, Nagasaki became the second target
Even after this second demonstration of catastrophic destructive power
it took almost another week for the Japanese government to finally accept defeat
and this only as a result of an
unprecedented intervention by the Emperor Hirohito
who forced his hardliners to bow to the inevitable
So the second world war was ended with no further allied military
losses on the battlefield but at a terrible cost of the Japanese civilian
population, and with it the spectre of Mutually
Assured Destruction that dominated the Cold War era.
Hiroshima and Nagasaki were essentially experiments in a new kind of warfare
whose full implications were not entirely understood at the time.
Were the Allies justified and used the atomic bombs to bring an end to the war?
Should they have stuck to the conventional plan as envisaged by Operation Downfall.
Were there any other potential alternatives?
Let us know what you think in the comments below.
Hello again, if you've enjoyed this video and would like
to see more in the series then please do log on to the IWM's YouTube
channel and like and subscribe there, thank you.