This is a difficult question to answer. Like any technology it can be both good and bad – it depends on how you use it. You could argue that the nuclear deterrent has helped to keep the peace over the last 50 years, and nuclear power (with all its associated risks) grew out of the weapons programme and is helping to give us low carbon electricity. I once spoke to someone who worked on the Manhattan project; he was asked if he regretted his part in developing atom bombs. He said that at the time it felt very much like a race for survival. Once the knowledge that it was possible to split an atom to release energy existed, it was only a matter of time before someone came up with a weapon and they were under huge pressure to develop something first. I’m not sure if any of them realised what the ultimate consequences would be.