Has North Korea changed the rules of nuclear disarmament?
The argument always made in favour of nuclear weapons is that they are a deterrent and shouldn't be used, but by having them you stop nations misbehaving. This doesn't seem to be working on North Korea. Bruce Kent is vice president of the Campaign for Nuclear Disarmament and Sir Malcolm Rifkind is the former defence secretary and foreign secretary. They discuss with Sarah Montague how what is going on in North Korea is impacting the argument for and against nuclear power. (Image: First test of atomic bomb. Credit: Getty Images)