The bigger problem is his refusal to accept that in some circumstances it may have to be used.
Nobody in their right mind wants their country to use a nuclear weapon, it is a necessary evil as a deterrent. It no longer holds any weight as a deterrent when the world knows your leader is either extremely unlikely to retaliate or just flat out not willing.
As an island, we put ourselves in an extremely vulnerable position.
He doesn't have to believe in it, but he should damn well say he does if he wants to be Prime Minister.