BBC Archive: Nuclear arms from Hiroshima to North Korea
On 6 August 1945, a nuclear bomb destroyed Hiroshima. Today nuclear warfare remains a threat to global security.
On 6 January 2016, North Korea claimed to have successfully carried out an underground hydrogen bomb test.
While the international community has been sceptical towards the North Korean claims, a trawl through the archives shows just how contentious an issue nuclear arms has been for over 70 years.