The United Nations vote to ban nuclear weapons made 85-year-old Setsuko Thurlow very happy. “I have been waiting for this day for seven decades and I am overjoyed that it has finally arrived,” she said.

She is one of the Hibakusha, the Japanese survivors of the atomic bombs that the US dropped on Hiroshima and Nagasaki in 1945 ending World War Two. “This is the beginning of the end of nuclear weapons,” she hoped.

But there’s a few big problems to solve first. Although Scotland has backed the new UN treaty, Westminster and the world’s eight other nuclear weapons states have rejected it.

A clear majority of the world’s countries – 122 – voted to ban the bomb, but the minority of nations with the bombs and the most power boycotted the whole process. They say they will not sign the new treaty, and they will continue to hold sway at the UN Security Council.

The UN, for all its virtues, is still a deeply unequal forum. If the big boys don’t want to get rid of their big toys, there’s little the rest of the world can do to force their hand.

But it is not hopeless. International moves to control chemical and biological weapons faced initial opposition. It was a long struggle to adopt the UN Nuclear Non-Proliferation Treaty, of which the UK government is now an ardent fan.

The reactions of the nuclear states to the new UN treaty have been intriguing. Instead of loftily ignoring it, they have been working furiously behind the scenes to sabotage it - and yesterday queued up to loudly condemn it.

Are they rattled? Do they fear that the UN’s move could actually be historic, and start a process that will see the world turning its back on weapons of mass destruction? As Setsuko Thurlow would say, here’s hoping.