"Of course, the deterrent is not cheap — no major equipment programme is. But our current nuclear weapons capability costs on average around 5-6 per cent of the current defence budget. That is less than 1.5 per cent of our annual benefits bill. And the successor submarines are, on average, expected to cost the same once they have entered service." David Cameron, the Telegraph, 4 April 2013
As North Korea zeros in on the United States, threatening an imminent nuclear attack on our historical ally, the debate has shifted towards the UK's nuclear deterrent.
Last time Trident took the spotlight in our national debate, it was 2010 and the Liberal Democrats' election pitch urged for a rethink of the government's nuclear policy - in particular relating to our fleet of submarines armed with Trident ballistic missiles - as a way to wrest the country's finances back on course.
Today the Prime Minister defended Britain's nuclear capability in an editorial in the Telegraph, arguing that "the security of our nation is worth the price."
But what is the price of Trident?
According to a series of statements made in Parliament by ministers of the MoD in 2008 and 2012 the annual operating costs of the Trident programme amount to around 5 to 6 per cent of the defence budget. That's the equivalent of between £2 to £2.4 billion.
What about Trident replacement?
The Government is in the process of deciding whether to replace the four submarines which carry nuclear warheads mounted on Trident missiles with a like-for-like replacement. The Trident successor programme will be funded from the Ministry of Defence's core equipment budget. (Source: House of Commons Library, Update on Trident Successor Programme)
In 2006 the Labour Government estimated that the procurement costs of the replacement of the Trident system would be in the region of £15-20 billion at 2006/07 prices.
The "Initial Gate" - the first stage of investment - for the Trident programme was announced at the House of Commons in May 2011 by the then Defence Secretary Liam Fox. The estimated costs confirmed the Labour government's estimates though at current prices including inflation that is now "£20 billion to £25 billion at out-turn."
Liam Fox also added:
"Between now and main gate [in 2016] we expect to spend about 15% of the total value of the programme. That is entirely consistent with defence procurement guidance. The cost of long lead items is expected to amount to about £500 million."
In November 2012 the Ministry of Defence (MoD) outlined its projections for year-on-year spending up to 2016/17. Between now and 2016/17 this totals £2.8 billion.
In December last year, the MoD also confirmed that once the new nuclear deterrent submarine comes into service, the "in-service costs of the UK's nuclear deterrent, including the costs of the Atomic Weapons Establishment, will be similar to today", at around 5-6% of the defence budget - which totalled £40 billion in 2011/12 - so between £2 to £2.4 billion.
So is the cost of Trident less than 1.5% of our annual benefits bill as the Prime Minister said?
Benefits expenditure by the Department for Work and Pensions for the financial year 2011/12 was £158.5 billion. That figure includes £74 billion of state pension but does not include Child Benefit which is dealt with by the taxman, who gave people £12 billion in 2011/12.
1.5% of that bill roughly totals £2.38 billion, which is roughly equal to but certainly not a lot more than the MoD's cost projections.
It looks like the figures cited by the Prime Minister were pretty sound, although they're not set in stone as the MoD is still in the process of reviewing Trident replacement.
Flickr image courtesy of the Ministry of Defence