Brown tells Clegg to 'get real' on nuclear arms - Sky News Leaders' Debate
is certainly controversial and expensive - but could you really do it differently and for less money?
Trident is a ballistic missile system based on four Vanguard-class submarines. The advantage of submarines is that they are hard for any enemy to find - and one boat is always on patrol, providing the UK with a continuous at-sea deterrent.
The government, in its 2006 White Paper on Trident, said building the replacements would cost between £15bn and £20bn. The system needs to be renewed because the second of the current boats will go out of service in 2024.
The government's estimate - in 2006 prices - includes between £11bn and £14bn for four boats, plus between £2bn and £3bn for the refurbishment of the replacement warheads, plus from £2bn to £3bn for infrastructure over the life of the submarines - including upgrades at Aldermaston.
That figure did not include the running costs, maintenance or refitting of the submarines, or additional costs in the missile programme from 2030, when the Trident D5 missile will be retired.
Opponents of Britain's nuclear weapons system, including Greenpeace, claim the full cost of replacing and running the Trident system on a like-for-like basis, as both Labour and the Conservatives have pledged to do, will be
between £80bn and £100bn in total.
That works out at around £2bn pounds per year over the system's expected lifetime of 40 years, or some 5% of the annual defence budget, which currently stands at £38bn a year.
Ballistic versus cruise
British governments have studied three times whether there are cheaper ways than Trident (or its predecessor) of achieving the same aims, but each study concluded that this type of system provided the most credible and reliable nuclear weapon.
Trident's ballistic missiles have a long range, of up to 7,500 miles. One alternative that has been suggested is using cruise missiles based on different submarines. However, cruise missiles have a far shorter range, of over 1,000 miles, and are slower and more vulnerable to being shot down.
Dr Lee Willett from RUSI explains Britain's options for strategic defence missiles
Whether other potential alternatives would be much cheaper in practice is also disputed. If Britain chose a cruise-missile system, it would probably have to develop its own missile programme, bearing all the research and development costs.
Dr Lee Willett, head of Maritime Studies Programme at the defence and security think-tank
Royal United Services Institute
, tells me a cruise missile has "neither the speed, the range or the survivability" of a ballistic missile.
He also says a cruise missile has significant consequences in terms of cost, as there is no hypersonic long-range cruise missile on the market - so Britain would have to look at developing one at great expense.
Others have suggested using a land-based delivery system, to avoid the cost of building new submarines. But that has been rejected in the past as too vulnerable to attack - and impractical on these crowded islands. The White Paper also concluded that the lifetime cost of this option would be double those of the submarine option.
Some say it would be cheaper to launch missiles from a long-range aircraft. However, the shorter range would again be an issue - and the aircraft could be brought down. The White Paper also examined having a large surface ship that could launch Trident missiles, but judged that the vessel would be too easy to detect.
So yes - there are alternatives to Trident. But they are not necessarily cheaper, nor able to do what the current system does. So if the UK decides it wants to remain a nuclear power, most defence experts believe Trident remains the only really credible option.
However, the Liberal Democrat suggestion that Trident should form part of the strategic defence review could re-open the debate, and arguments over Trident may well prove attractive to voters - not least those who ask if the UK should remain a nuclear-armed state at all.
A selection of your comments are below.
We should hand over the nuclear deterrent to the EU and let the 26 member states share the cost, that way we get the protection at a fraction of the cost. Kevin, London
It really is extraordinary that there are still so many naive people who believe that by giving up nuclear weapons we will make Britain - and the world - a safer place. There were similar fools about just before the second world war who wanted to get rid of the RAF because of the horrific consequences of bombing. Thanks heavens we did not listen to them. Guy, London
The money for Trident could be used to fund better intelligence services to detect and deter would-be terrorists. David, Milton Keynes
Everyone here is talking about the threat now, but Trident is not due to come into service for 14 years. Who can predict what threats there will be to world peace in 14 years time, from developing nuclear nations such as Iran and North Korea? Claudia, Marlow
The UK has an opportunity to set a shining example to the world by being the first nation to give up nuclear weapons Nick, Hampshire
We need to keep Trident. If nuclear arms was not important in today's world why do Iran and other countries desperately try and get this capability. It's not just a deterrent as well, building the astute class subs keeps a lot of highly skilled and unique engineers in work, if we stopped we would lose the skills forever! Dan, Guildford
The main threat today to our safety are the small groups out there and not a single country, the smaller groups who would use dirty bombs and other low-tech ways of attacking us. But this has not always been the case and who can predict what will happen between great powers in the future. Trident may become our main deterrent against attack once again. Just because right now it seems a waste of money to replace our nuclear deterrent does not mean this is the way it will always be. Craig, Bedlington
The alternative to Trident is simple. Better health service and more police on the beat. We are paying billions of pounds to protect against a nuclear threat that might happen - but even then mutual destruction is hardly beneficial. No missile can stop another London underground bombing. Trident wont ward off a terrorist armed with bacteriological weapons. We need to drop the nuclear posturing and concentrate our spending on making day to day life better for all our citizens. Nick, Hove
If Trident is manufactured using a large proportion of UK resources then the money doesn't leave the country. And it supports UK jobs, intellectual property and skills development. So what is the problem. If the alternatives are imported (from America) then the cash does leave, we lose the jobs skills and knowledge and hence devalue Britain. Billy, Cheshire
When USA and Russia have agreed to reduce their nuclear armoury, Obama is talking about a world without nuclear weapons and Britain is skint, does it make any sense to renew a system that's likely to provoke other nations to obtain nuclear capability? We should also be working for reform of the UN so that possession of nuclear weapons does not earn entitlement to a permanent seat on the Security Council. P. Harding, London
The argument about the systems is completely irrelevant. The key question is does Britain need (or can afford) a late 20th century concept to defend its people in the early 21st century? When the more likely threats are from terrorists (foreign & home grown) who will employ simpler and cheaper ways of causing destruction (9/11, dirty bombs and chemical weapons etc) what good are submarines patrolling around with nuclear warheads. It is no 'insurance policy' against terrorists & therefore a waste of our limited resources. Steve, Alfreton, Derbyshire
Succinctly: a) we do need a nuclear deterrent b) we need to constantly review perceived threats c) we no longer need cold war defences d) we do need a credible and mobile response e) we need to understand that future enemies may not be deterred by retaliation. Its a bit late then anyway f) a European solution should be preferred with cost spread across all members of EU and NATO. Richard, Norwich
Just whom is Trident supposed to deter? The current threat to world security comes from faceless amorphous groups who are prepared to use their own people to deliver death via suicide attacks. Are they likely to be deterred by the threat of a nuclear strike? And what would we aim such a strike at? Cameron and Brown are living in the past like a couple of old generals preparing to fight tanks with mounted cavalry. Get real boys. Or at the very least get up to date. Neil, Nantwich
What does it matter if we lose, or limit, our nuclear deterrent? Germany and Japan are both doing very well without one. Britain seems obsessed with punching above it's weight - we're no longer a huge empire. We need to try to scale back our ambitions. Even if we had a full array of nuclear weapons, I can't foresee any plausible scenario in which we'd actually use them. Who would want to be remembered as the Prime Minister that killed millions of innocent civilians by nuking a city in a revenge attack? Ian, Saffron Walden
In the current uncertain times and even more uncertain future of the world, it always pays to have the best deterrent "insurance" policy. So yes we should renew Trident. There are no other options which give the same performance. Hopefully it will never be used but its stupid to say its a waste of money. Who see's that having an insurance policy you pay for and never use (car, travel etc) is a waste? Jon, Basingstoke
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