GCSE · History · AQA · Spec 8145

Dropping of the atom bomb and superpower relations

Imagine your ally is fighting the same enemy as you, and you secretly build the most powerful weapon ever made without telling them. What will they do about it?

History · Cause and consequence

One weapon, several knock-on effects

The USA built the atomic bomb in secret and used it on Japan in 1945. Did that make life easier or harder between the USA and the USSR? Add the links you think connect these factors (which one led to which?), then compare with the lesson's web.

The USA's atomic bomb, kept secret from its Soviet ally until the Potsdam Conference
Stalin's anger and suspicion
A harder Soviet line and tighter control of Eastern Europe
The Soviet atomic bomb, tested 29 August 1949
The arms race
Greater tension between the USA and the USSR (outcome)
Possible reluctance to go to war

Add a link

This factor……made this happen or worse

No links yet.

Exam line: Good explanations don't list consequences. They show how one led to the next.

History · Trust between allies

When did the distrust start?

During the Second World War the USA and the USSR were on the same side, fighting alongside Britain as part of the Grand Alliance. Allies. Friends, surely?

Which is closest to what you think right now? When did serious distrust between the USA and the USSR begin?

Even during the war, when they were cooperating. The USA kept the Manhattan Project from the USSR and Soviet spies were at Los Alamos.Only after the war ended. As allies, they trusted each other completely until 1945.Only once the atomic bombs were used on Japan in 1945. The bombs created the distrust.Only when the USSR tested its own bomb in 1949.

How sure are you?

I'm sureI think soI'm guessing

Even during the war, when they were cooperating. The USA kept the Manhattan Project from the USSR and Soviet spies were at Los Alamos.

This matches the evidence

Yes. The USA kept the Manhattan Project secret from its Soviet ally, and the USSR spied on it, with Soviet spies penetrating security at Los Alamos, New Mexico. Secrecy on one side and espionage on the other show a lack of trust at the height of wartime cooperation.

Only after the war ended. As allies, they trusted each other completely until 1945.

This is a common misconception

It's an easy assumption: allies fight the same enemy, so surely they trust each other. But the project that produced the bomb was top secret, hidden from the USSR, and Soviet spies were working inside it while the war was still on. Cooperation and trust are not the same thing.

Only once the atomic bombs were used on Japan in 1945. The bombs created the distrust.

This is a common misconception

The bomb did make things worse (you saw how in the web), but it didn't start the problem. The secrecy and spying came first. Think of the bomb as pouring petrol on a fire that was already smouldering. The distrust was there before it landed.

Only when the USSR tested its own bomb in 1949.

This is a common misconception

By 1949 the bomb had been used and the Soviet test was the result of distrust, not the start of it. And the Long and Novikov Telegrams of 1946, which you'll meet in a moment, already show relations had become very hostile three years earlier.

Distrust didn't begin with the bomb. It was already there in wartime, and the bomb made it worse.

Exam line: Don't write that the allies trusted each other until the bombs. The secrecy and the spying say otherwise.

History · Chronology

Put the story in order

when it happened, earliest first

1 · Earliest7 · Latest

The USSR tests its own atomic bomb
Truman tells Stalin at the Potsdam Conference that the USA has nuclear weapons
Japan surrenders
The USA begins the top secret Manhattan Project
The Long Telegram is sent
Atomic bombs are dropped on Hiroshima and Nagasaki
The Trinity Test

Exam line: A later event can't be a cause of an earlier one. Getting the order right protects your explanation.

History · Interpretations

Why were the bombs used?

Three views, set side by side. No winner is chosen for you.

Why were the atomic bombs used against Japan in August 1945?

Truman and many others

The bombs were used to force Japan to surrender.
Japan surrendered on 15 August 1945, and they argued it only happened so quickly because of the destruction of Hiroshima and Nagasaki.

Historians who say the bombs were not necessary

Some historians

The bombs were not necessary to win the war.
Their main purpose was to demonstrate American power, especially to the USSR.
They also served to give countries in Western Europe confidence that the USA could protect them, and to strengthen the USA's bargaining position with the USSR.

Stalin's own view

Stalin

The bomb was American blackmail.

Common ground

Atomic bombs were used on Hiroshima and Nagasaki in August 1945.
Japan surrendered on 15 August 1945.

Compare the positions, then weigh them yourself.

No verdict here

The decision to use the bombs remains deeply controversial, and historians disagree about the motivation. Each view above is an interpretation to attribute, not a fact to state.

Comparing 3 positions: Truman and many others, Historians who say the bombs were not necessary, Stalin's own view.

Exam line: Attribute every explanation of motive: say whose view it is.

Two telegrams, two mirror-image fears

Tap each topic and compare the American and Soviet sides. Look for the shared ground.

The Long Telegram (USA, 1946)

George Kennan, a US diplomat, writing on 22 February 1946.

The Novikov Telegram (USSR, 1946)

Nikolai Novikov, a Soviet official in Washington, writing in 1946.

History · Exam practice

Now you write it

Explain how the development and use of the atomic bomb affected relations between the USA and the USSR. [6 marks]

Your answer

0 words · your answer stays on this page and is not sent anywhere.

The mark scheme

Stalin resented learning of the Manhattan Project only at Potsdam and suspected Truman was trying to intimidate the USSR. (1 mark)
The USSR refused to be bullied: Stalin hardened his line. (1 mark)
Soviet control tightened over Eastern Europe, creating a buffer zone of friendly communist states, which raised tensions further. (1 mark)
The USSR built its own bomb and tested it on 29 August 1949, fearing the USA could otherwise blackmail it. (1 mark)
With cities now destroyable by both sides, tension grew dramatically and an arms race began. (1 mark)
The Long and Novikov Telegrams (1946) show how hostile relations had become. (1 mark)
Balancing point: fear of the bomb's terrible consequences may have made war less likely. (1 mark)

Model answer

The bomb made things worse between the superpowers in a chain of ways. Stalin resented hearing about the Manhattan Project so late and suspected Truman of trying to bully him, so he refused to back down and clamped down on Eastern Europe, creating a buffer zone that raised tension. Fearing American blackmail, the USSR built and tested its own bomb in 1949, four years after the USA, and each side then raced to build more powerful weapons. The Long and Novikov Telegrams of 1946 show how hostile things had become. One possible upside is that the terrible consequences may have made both countries more reluctant to fight.

Link your consequences (angry, harder line, buffer zone, Soviet bomb, arms race) and finish with the one 'may have' that pulls the other way.

Exam line: Aim for linked consequences, each backed by specific knowledge, not a list of events.

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

How a weapon kept secret from an ally made the USA and the USSR trust each other even less

What you need to know

In 1942 the USA, with British and Canadian support, began the top secret Manhattan Project to beat its enemies to the atomic bomb.
The USA hid the project from its Soviet ally, but Soviet spies penetrated security at Los Alamos, where the bomb was built.
Secrecy on one side and spying on the other show how little the allies trusted each other, even in wartime.
Truman had the Potsdam Conference pushed back until after the Trinity Test of 16 July 1945, then told Stalin the USA had nuclear weapons.
Have a goTruman had the start of the Potsdam Conference pushed back. Did he move it earlier or later, and which event did he want to come first?
Later, so that it took place after the successful Trinity Test.
Pushing back means moving later. The conference was timed to come after the bomb had been tested, not before.
Hiroshima was bombed on 6 August 1945 and Nagasaki on 9 August. It is estimated that over 120,000 civilians were killed.
Have a goA classmate swears the notes say 'exactly 120,001 civilians died'. Is that how you should report it?
No. Report it as an estimate: over 120,000 killed by the two bombs.
The figure is only an estimate, so use 'an estimated' or 'over'. A precise number would claim more certainty than the evidence gives.
Japan surrendered on 15 August. Truman and many others said the bombs forced it, but historians disagree about why they were used.
Stalin, angry at being told so late, saw intimidation, took a harder line and tightened control of Eastern Europe as a buffer zone.
Have a goSuppose Truman hoped the bomb would make Stalin easier to deal with. Using what you've just read, did it work?
No. Stalin took a harder line and tightened his grip on Eastern Europe.
Feeling intimidated didn't make Stalin back down. He wanted to show the USSR couldn't be intimidated, so the effect was the opposite of what a hopeful Truman would want.
The USSR tested its own atomic bomb on 29 August 1949, four years after the USA.
Tension rose and an arms race began, though the terrible consequences of using the bomb may have made war less likely.
The Long Telegram and the Novikov Telegram, both from 1946, show relations had become very hostile.

The big picture

The USA built the atomic bomb in secret and kept it from its Soviet ally. When it was used in 1945, Stalin took a harder line, tightened control of Eastern Europe and built a bomb of his own, and an arms race followed. Historians disagree about why the bombs were used, and the one hopeful note is that their terrible consequences may have made war less likely.

Key points

1The Manhattan Project (1942) was top secret, hidden from the USSR, and Soviet spies were inside Los Alamos. Distrust existed even in wartime.

2Why the bombs were used is a debate. Truman and many others said it was to force Japan to surrender. Some historians say the main purpose was to demonstrate American power, especially to the USSR. Stalin saw American blackmail.

3Stalin was angry at being told only at Potsdam. He took a harder line and tightened control of Eastern Europe as a buffer zone, which increased tensions.

4The USSR tested its own bomb on 29 August 1949, four years after the USA, and an arms race followed.

5The one counter-link: the terrible consequences of using an atomic bomb may have made both countries more reluctant to go to war.

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Worked example

Problem

A student writes: 'Truman dropped the bombs to scare Stalin.' Rewrite it as accurate history.

⚠ Watch out

Writing 'the bomb was dropped to scare Stalin' as if it were a fact. That is one historians' view. Truman and many others gave a different reason. Always say whose view it is.

🧠

Memory hook

Secret → Suspicion → Soviet bomb → Arms race. Four steps, and the first one was the USA's own secret.

✓

Check yourself

Without looking back: name three ways the bomb worsened relations between the USA and the USSR, and the one reason it may have made war less likely.

Flashcards

(15)

What was the Manhattan Project?

The USA's top secret project, begun in 1942 with support from Britain and Canada, to develop the atomic bomb before Nazi Germany or any of its other enemies.

Where did Soviet spies get into the Manhattan Project?

Los Alamos, New Mexico, where the bomb was being developed.

What did the secrecy and the spying show?

A lack of trust between the USA and the USSR, even at the height of their wartime cooperation.

What was the Trinity Test?

On 16 July 1945 the USA successfully detonated the world's first atomic bomb in the New Mexico desert.

What did Truman do about the start of the Potsdam Conference?

He pushed it back so it took place after the successful test. At Potsdam he told Stalin the USA had nuclear weapons.

When were Hiroshima and Nagasaki bombed?

Hiroshima on 6 August 1945 (by the Enola Gay, a B-29) and Nagasaki on 9 August 1945.

How should you give the death toll of the two bombs?

As an estimate: over 120,000 Japanese civilians killed, some instantly and many later from burns or radiation sickness.

Whose view is it that the bombs forced Japan to surrender?

Truman's and many others'. Japan surrendered on 15 August 1945.

What do historians who say the bombs were not necessary argue?

That their main purpose was to demonstrate American power, especially to the USSR, reassure Western Europe and strengthen the USA's bargaining position with the USSR.

How did Stalin see the bomb?

As American blackmail.

What was Stalin's 'buffer zone'?

Friendly communist countries in Eastern Europe, between Germany and the USSR's western border, kept under Soviet control.

When did the USSR test its own atomic bomb?

29 August 1949, four years after the USA.

What was the arms race?

The USA and USSR each tried to ensure their nuclear weapons were more powerful than their rival's.

How might the bomb have made war less likely?

Its terrible consequences may have made both countries more reluctant to go to war. It's a 'may have', not a certainty.

What did the Long and Novikov Telegrams reveal together?

That relations between the USA and the USSR had become very hostile by 1946.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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One weapon, several knock-on effects

When did the distrust start?

Put the story in order

Why were the bombs used?

Truman and many others

Historians who say the bombs were not necessary

Stalin's own view

Now you write it

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