Togo....none of those countries are ever going to drop a nuclear bomb on Britain.
The main reason why we thought we needed nuclear weapons was that America used us as a stationary aircraft carrier, moored just off the coast of Europe, for many years. Those American bases would have been the targets for Russian missiles, not the rest of Britain.
Pakistan and India might very well drop one on each other, and Israel might let one off if somebody poked them hard enough in the backside. Ditto with the Mad Dog state of N Korea, but I still can't see how nuclear missiles protect Britain, or from whom.
When Argentina invaded the Falklands, we sent a modern Armada, together with some Vulcan bombers, instead a Trident missile. Of course, we don't have any aircraft carriers now !
Our economy could be completely transformed if we had the guts to cancel the program to replace Trident. Canada, Australia, New Zealand, all of South America, most of Asia, and almost all of Europe seem to get along very well without nuclear weapons, so why do we need them ?