The question is basic to deterrence; How many weapons are necessary to deter an attack? Five, ten twenty, two hundred, two thousand? If the US radically reduces its nuclear arsenal, would that not be an incentive for most any power to merely accumulate a half dozen and join the club?
Barack Obama ready to slash US nuclear arsenal
Pentagon told to map out radical cuts as president prepares to chair UN talks
President Obama's decision to order a review comes as he takes the rare step of chairing a watershed session of the UN security council.
Barack Obama has demanded the Pentagon conduct a radical review of US nuclear weapons doctrine to prepare the way for deep cuts in the country's arsenal, the Guardian can reveal.
Obama has rejected the Pentagon's first draft of the "nuclear posture review" as being too timid, and has called for a range of more far-reaching options consistent with his goal of eventually abolishing nuclear weapons altogether, according to European officials.
Those options include:
• Reconfiguring the US nuclear force to allow for an arsenal measured in hundreds rather than thousands of deployed strategic warheads.
• Redrafting nuclear doctrine to narrow the range of conditions under which the US would use nuclear weapons.
• Exploring ways of guaranteeing the future reliability of nuclear weapons without testing or producing a new generation of warheads.
The review is due to be completed by the end of this year, and European officials say the outcome is not yet clear. But one official said: "Obama is now driving this process. He is saying these are the president's weapons, and he wants to look again at the doctrine and their role."
The move comes as Obama prepares to take the rare step of chairing a watershed session of the UN security council on Thursday. It is aimed at winning consensus on a new grand bargain: exchanging more radical disarmament by nuclear powers in return for wider global efforts to prevent further proliferation.
That bargain is at the heart of the nuclear non-proliferation treaty, which is up for review next year amid signs it is unravelling in the face of Iranian and North Korean nuclear ambitions.
In an article for the Guardian today, the foreign secretary, David Miliband, argues that failure to win a consensus would be disastrous. "This is one of the most critical issues we face," the foreign secretary writes. "Get it right, and we will increase global security, pave the way for a world without nuclear weapons, and improve access to affordable, safe and dependable energy – vital to tackle climate change. Get it wrong, and we face the spread of nuclear weapons and the chilling prospect of nuclear material falling into the hands of terrorists."
According to a final draft of the resolution due to be passed on Thursday, however, the UN security council will not wholeheartedly embrace the US and Britain's call for eventual abolition of nuclear weapons. Largely on French insistence, the council will endorse the vaguer aim of seeking "to create the conditions for a world without nuclear weapons".
Gordon Brown is due to use this week's UN general assembly meeting to renew a diplomatic offensive on Iran for its failure to comply with security council demands that it suspend enrichment of uranium. The issue has been given greater urgency by an International Atomic Energy Agency document leaked last week which showed inspectors for the agency believed Iran already had "sufficient information" to build a warhead, and had tested an important component of a nuclear device.
Germany is also expected to toughen its position on Iran ahead of a showdown between major powers and the Iranian government on 1 October. But it is not yet clear what position will be taken by Russia, which has hitherto opposed the imposition of further sanctions on Iran.
Moscow's stance will be closely watched for signs of greater co-operation in return for Obama's decision last week to abandon a missile defence scheme in eastern Europe, a longstanding source of irritation to Russia.
"I hope the Russians realise they have to do something serious. I don't think a deal has been done, but there is a great deal of expectation," said a British official.
Russia has approximately 2,780 deployed strategic warheads, compared with around 2,100 in the US. The abandonment of the US missile defence already appears to have spurred arms control talks currently underway between Washington and Moscow: the Russian president, Dmitry Medvedev, said today that chances were "quite high" that a deal to reduce arsenals to 1,500 warheads each would be signed by the end of the year.
The US nuclear posture review is aimed at clearing the path for a new round of deep US-Russian cuts to follow almost immediately after that treaty is ratified, to set lower limits not just on deployed missiles but also on the thousands of warheads both have in their stockpiles.
The Obama strategy is to create disarmament momentum in the run-up to the non-proliferation treaty review conference next May, in the hope that states without nuclear weapons will not side with Iran, as they did at the last review in 2005, but endorse stronger legal barriers to nuclear proliferation, and forego nuclear weapons programmes themselves.
"The review has up to now been in the hands of mid-level bureaucrats with a lot of knowledge, but it's knowledge drawn from the cold war. What they are prepared to do is tweak the existing doctrine," said Rebecca Johnson, the head of the Acronym Institute, a pro-disarmament pressure group. "Obama has sent them it back saying: 'Give me more options for what we can do in line with my goals. I'm not saying it's easy, but all you're giving me is business as usual.'"