Treaty signatories include Africa’s most populous country and Europe’s least populated, but Russia and Nato on the sidelines
An international treaty banning all nuclear weapons that has been signed by 51 countries and that campaigners hope will help raise the profile of global deterrence efforts comes into force on Friday.
Although in some respects the step is largely symbolic because the world’s nuclear powers have not signed up, the treaty will be legally binding on the smaller nations that have endorsed it, and it is backed by the UN leadership.