Deterrence

Nuclear weapons are very dangerous and also very expensive though not as much as the delivery systems.
Currently the government are about to spend £80 billion on the Trident delivery system, it's not so much the cost but the fact that it is submarine based that makes it expensive, the advantages are however manifold.

1. The warheads are safe from interdiction interception from those out there who would do us harm.
2. Land based rockets can be got at far more easier than submarines.
3. Aircraft can (and are) shot down far easier than a submarine.
4. Our nuclear subs can strike back from anywhere at any time.
5. Those who would do us harm will never know where or when our revenge would come from as they don't have the means to detect our subs.

So when I saw this article I knew straight away it was an attempt to smash and grab the Trident budget rather than any serious thought given as to what would happen if Iran got  nuclear weapons or Pakistan fell to Islamic fundamentalists.

Times.

Britain should be prepared to scrap its nuclear deterrent, a group of generals write in The Times today, pushing the future of Trident to the forefront of the election.

The generals say that the next government would threaten both frontline Forces and global disarmament talks unless it considers different ways of spending the £80 billion required to replace the fleet of submarines.

Their intervention, although nonpolitical, offers timely support for Nick Clegg, who goes into tomorrow night’s foreign affairs debate with Gordon Brown and David Cameron as the only party leader arguing against a like-for-like replacement. 

Since 2007, when the Government decided to replace Trident, the debate has shifted significantly, they write, and there is now a “growing consensus that rapid cuts in nuclear forces ... is the way to achieve international security”. Pressing ahead regardless with a costly replacement could upset President Obama’s international disarmament drive, they say. And money spent on nuclear weapons would be unavailable for frontline troops, counter-terrorism work, helicopters, armoured vehicles, frigates or manpower.

They argue that any genuinely comprehensive review needs to answer the question: “Is the UK’s security best served by going ahead with business as usual, reducing our nuclear arsenal, adjusting our nuclear posture or eliminating our nuclear weapons?”

Personally I don't trust president Obama's disarmament drive, that will only work for civilised countries, North Korea and Iran are not particularly trustworthy where it comes to rhetoric and belligerence, nor do I trust the Pakistani state to remain stable. All of those will pose future threats to civilisation and non will hand over their nuclear weapons I suspect they think Obama's a fool too.
The government have short changed the frontline troops of equipment from day 1, I rather doubt £80 billion will be given to the generals rather than the Navy to play with, far better spent on keeping the governments client state pets happy with bread and circuses.
Clegg's argument that other states shelter under Americas nuclear umbrella may have been true in the cold war but certainly isn't so today, America might retaliate if an ally is attacked, then again they may not, far better to have our own deterrence anyway, particularly one where they wont see it coming until too late.

Yes I know it's expensive, but it's a far better deterrent than any other option and whilst I'm all in favour of funding our armed forces properly, I don't think it should be done at the expense of Trident.