Trident

Rhetoric is a powerful weapon. Listening to a debate on the use of Trident, the applause was greatest when the wish for a better world was linked to disarmament. It's a wish that has carried the hope of so many good minded people.
The belief that mankind is represented by our own good intentions is seriously challenged by the sight of ISIS chopping off heads or the sabre rattling from the geeky head of North Korea but people continue to see others in their own light.
People are persuaded in matters such as this. They have no way of knowing the facts, there is no way of defining the dangers, other than reaching back into the historical context.
War used to be between nations supported by diplomacy, having treaties with other nations and undertaken when the national economic effort had produced an arsenal to fight with.
Today the nations who would have been 'watched' in the past are members of an established Global experiment which has to a large extent, minimised 'nationalism' and boarder expansion.
Of the nuclear nations.
USA is streets ahead of everyone else.
Russia has its Cold War armament to fall back upon and has been spending a massive amount on modernisation.
China is an unknown in so far as it has nuclear weapons or the effect of its enormous economic clout could make on its acquisition, but historically is not known for having ambitions outside its boarders.
India and Pakistan are both subject to domestic politics and a religious divide but don't seem to have much interest in issues outside their collective boarders.
France has resolutely stayed in the game, not only in continuing to hold nuclear weapons but in the lead it has maintained in the domestic nuclear industry both design and production.
Israel has, with American blessing its own nuclear system which given the volatility of the Middle East and the countries around it which hate its guts, one could see a position that when threatened with total annihilation it could fire off its missiles in the hope that the promised land in the afterlife would be some sort of compensation.
The UK has reduced its nuclear arsenal to a shadow of what it was. We no longer have nuclear bombs which can be dropped by aircraft, there is no land-based missile delivery system, and we  have relinquished the tactical nuclear weapons used on the battlefield. The last and only nuclear weapon is the Trident platform where we provide, 'American weapons' with the stealth that a submarine brings. We can't fire it unless the Americans agree but kid ourselves that we have some sort of deterrent.
In a volatile world where cultures threaten our own it is important to feel that we aren't impotent when it comes to standing up to bullies. Having the headmaster on your side is useful but when he changes his own allegiance you need to have practised martial arts to feel you can protect yourself . The universal disarmament brigade fasten their banner to a world where there are no bullies and disagreement can be negotiated. Unfortunately the world is not made up of rational human brings and we have to provide the ultimate answer to the bully, bugger off or I will thump you back.
Trident as costly as it is,does not provide the answer to the bully but at least it makes him think twice before he starts.