The problem with Cameron’s argument is that a nuclear weapon is only effective if you do not use it. Can you imagine a non-nuclear state being attacked by a nuclear state? Can Cameron imagine giving the order if he was told that a possibly nuclear missile was headed toward Newcastle? How would he respond? We assume that nuclear weapons protect us from nuclear war, but it is more correct to consider that they make conventional war far more of a risk with a nuclear armed state.
A nuclear exchange we presume would come from somewhere else, but it was the USA and UK that occupied Iraq in no small part due to being able to sell the fear of their (fictional) WMD stockpile. We were more likely to use WMD than Saddam. North Korea and Iran may well be a threat. If Iran attacked the UK with nuclear bombs many innocents and many many Muslims would be killed so it not likely. North Korea can not bomb the targets they keep boasting about, and then have enough to bomb the UK as well. It is also hard to imagine what an enemy would want from a radioactive Britain. It is the balance of our actions and theirs that is the real deterrent.
In the end progress and civilisation have overtaken barbarity but we still do not believe we can trust other human beings because they are like us.
Why even worry about a new Trident? The older bombs still deter fairly effectively. Why not spend the dosh intelligently so that we can protect vessels from pirates, air planes from terrorism and and our citizens from road accidents. More lives would be saved.
And in response to a post with the usual rational argument supporting Trident as an effective deterrent when the rest of the military seems to be under equipped in the aircraft carrier department.
Respectfully, these are very well trod arguments for spending money in a way that produces nothing of any value except to scare off dictators. There simply has to be a better way to deter potential adversaries than threatening to kill every living thing if they became too hard to beat with conventional weapons. Strong conventional forces are also a deterrent – one that can actually be employed. The argument should not be won by the logic of threatening to use weapons that we can not. It should be in comparison with spending those funds differently to protect ourselves successfully.