Nuclear weapons have been back in public conversation recently - partly due to rising tensions between Iran and Israel. Outside of the news, they have also been featured a lot in films and TV shows. (Think Oppenheimer and Fallout).

But, what are nuclear weapons? And is it likely they’ll be used again? Or, have we learnt from what happened in Hiroshima and Nagasaki?

The BBC's security correspondent Gordon Corera explains. We also hear from a nuclear studies student in Islamabad, Pakistan, about why young people should care about them.

Plus, Alex Rhodes from the team talks us through some nuclear close calls. This includes how the actions of one Stanislav Petrov could have saved us all.

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