The Timeline: The Atomic Bomb

Purification of uranium, 1939-1945

The first atomic bomb ever used in warfare was dropped on Hiroshima on 6 August, 1945 by the US – signalling the realisation of the six-year Manhattan Project. Albert Einstein had written to Franklin D Roosevelt in 1939 detailing the Nazi experiments that attempted to purify uranium, prompting the US to pump more than $2bn into its development. But it was Robert Oppenheimer – an American physicist working on the project – whose name became synonymous with the A-bomb. The success of the "gadget", the first atomic bomb, began the move into the "Atomic Age".

Hiroshima and Nagasaki, 1945

On 26 July, the US President, Harry S Truman, issued the Potsdam Declaration as an ultimatum to Japan, warning of the "inevitable [and] utter devastation" of Japanese homeland. Their refusal to surrender led to Enola Gay, a B-29 bomber, dropping the atomic bomb, known as Little Boy, on Hiroshima days later. Around 66,000 died instantaneously. The total reported number of deaths – from burns and radiation – varies from 90,000 to 166,000. Little Boy's brother, Fat Man, was dropped on Nagasaki three days later, killing 40,000 at once. On 10 August, the Japanese surrendered.

The Iron Curtain closes, 1946-1969

Relations between the East and West deteriorated severely as post-war Europe was carved up and the Iron Curtain descended and the Cold War began. The Soviet's expansion into the uranium-rich Eastern Bloc challenged America's monopoly over nuclear power and triggered the Arms Race, as the UK, France and China also developed weapons. The Korean War (1950-53) threatened atomic warfare once again. The defining crises of Berlin, 1961 and Cuba, 1962, narrowly avoided all-out conflict as the Cold War ran its course.

Nuclear Disarmament, 1970-1990

The Nuclear Non-Proliferation Treaty came into force in 1970, aiming to limit the powers with nuclear weaponry to five. The Campaign for Nuclear Disarmament argued for a more radical approach and gained widespread support. However, India, Pakistan and Israel all declined to sign the treaty, continuing to develop nuclear weapons. Mikhail Gorbachev's rise to power in Russia resulted in the end of both the Soviet Union and, ultimately, the Cold War, as the Berlin Wall fell. Relations between the US and Russia eased during this period.

The Modern Age, 1991-today

In 2003, North Korea became the first country ever to withdraw from the Non-Proliferation Treaty, as a US-led invasion of Iraq searched for weapons. Iran has continued to defy UN sanctions, with 21st-century nuclear policy increasingly dominated by the fear of "rogue states" developing weapons. The Liberal Democrats – during the 2010 election campaign – called for the cancellation of the renewal of the Trident missile programme.

Start your day with The Independent, sign up for daily news emails
ebooksAn unforgettable anthology of contemporary reportage
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Business Development Manager / Sales - OTE £45,000

£35000 - £45000 per annum: Recruitment Genius: This company is a solutions / s...

Recruitment Genius: Sales Executive - OTE £45,000

£18000 - £45000 per annum: Recruitment Genius: A Sales Executive is required t...

Recruitment Genius: Test Development Engineer

£35000 - £40000 per annum: Recruitment Genius: Are you inspired to bring new a...

Recruitment Genius: Trainee Motor Engineer

£14000 - £18000 per annum: Recruitment Genius: This is an exciting opportunity...

Day In a Page

Sepp Blatter resignation: The beginning of Fifa's long road to reform?

Does Blatter's departure mean Fifa will automatically clean up its act?

Don't bet on it, says Tom Peck
Charles Kennedy: The baby of the House who grew into a Lib Dem giant

The baby of the House who grew into a Lib Dem giant

Charles Kennedy was consistently a man of the centre-left, dedicated to social justice, but was also a champion of liberty and an opponent of the nanny-state, says Baroness Williams
Syria civil war: The harrowing testament of a five-year-old victim of this endless conflict

The harrowing testament of a five-year-old victim of Syria's endless civil war

Sahar Qanbar lost her mother and brother as civilians and government soldiers fought side by side after being surrounded by brutal Islamist fighters. Robert Fisk visited her
The future of songwriting: How streaming is changing everything we know about making music

The future of songwriting

How streaming is changing everything we know about making music
William Shemin and Henry Johnson: Jewish and black soldiers receive World War I Medal of Honor amid claims of discrimination

Recognition at long last

Jewish and black soldiers who fought in WWI finally receive medals after claims of discrimination
Beating obesity: The new pacemaker which helps over-eaters

Beating obesity

The new pacemaker which helps over-eaters
9 best women's festival waterproofs

Ready for rain: 9 best women's festival waterproofs

These are the macs to keep your denim dry and your hair frizz-free(ish)
Cycling World Hour Record: Nervous Sir Bradley Wiggins ready for pain as he prepares to go distance

Wiggins worried

Nervous Sir Bradley ready for pain as he prepares to attempt cycling's World Hour Record
Liverpool close in on Milner signing

Liverpool close in on Milner signing

Reds baulk at Christian Benteke £32.5m release clause
On your feet! Spending at least two hours a day standing reduces the risk of heart attacks, cancer and diabetes, according to new research

On your feet!

Spending half the day standing 'reduces risk of heart attacks and cancer'
With scores of surgeries closing, what hope is there for the David Cameron's promise of 5,000 more GPs and a 24/7 NHS?

The big NHS question

Why are there so few new GPs when so many want to study medicine?
Big knickers are back: Thongs ain't what they used to be

Thongs ain't what they used to be

Big knickers are back
Thurston Moore interview

Thurston Moore interview

On living in London, Sonic Youth and musical memoirs
In full bloom

In full bloom

Floral print womenswear
From leading man to Elephant Man, Bradley Cooper is terrific

From leading man to Elephant Man

Bradley Cooper is terrific