The Russian and American presidents agreed during their first meeting in London in April upon an immediate start to new START talks.

Both Russia and the US have to move fast to establish a new agreement, since the old one is due to expire in just six months. The talks were not held before since the US unilaterally withdrew from the anti-ballistic missile treaty in 2001.

Daryl Kimball, executive director of the Arms Control Association said, “START establishes ceilings on the delivery systems that are by today’s standards extremely high”.

“In addition, the verification and monitoring provisions were established during that era when there was far less trust in transparency than there is today,” he said.

A new treaty is necessary – one that would not limit just the quantity of nuclear warheads.

President Medvedev, during his official visit to Helsinki in April said:

"In the treaty which is to replace the START treaty, we need to limit not only the number of nuclear warheads, but also the means of delivery.”

However, despite both sides' apparent willingness to lead the way in nuclear reductions, there are worries that discrepancies in the amount of nuclear warheads held by Russia and the US could complicate the talks.

A report recently published by the Federation of American Scientists (FAS) shows the United States to have a much smaller nuclear stockpile than Russia. So the big question is: how accurate are these figures?

Hans Kristensen from the FAS commented:

“The START treaty doesn’t really count the actual weapons that are on the systems. It assigns an artificial number to each delivery platform and from that you get what’s called aggregate numbers. So, the challenge for the new agreement is to try to get closer to a real number.”

Numbers aside, there is another potential issue in the works. According to Russia’s Foreign Minister Sergey Lavrov, Russia wants the new START treaty to regulate the US-led anti-missile defence plans for Eastern Europe.

“Shaping the new treaty we must take into account global security. And this, of course, presumes we have to sort out things with the anti-missile defence,” he said.

Moscow vehemently opposes Washington's plans to deploy elements of its anti-missile defence shield in Poland and the Czech Republic. A lot of potential stumbling blocks are on the road to agreement.

So how long will this new treaty take before materialising from discussion topic into reality?

Joseph Cirincione, President of the Ploughshares Fund, and a personal friend of U.S. negotiator Rose Gottemoeller, says he hopes both countries will be nuclear-weapons free within a couple of decades.

“Both sides recognize that nuclear weapons are more likely to be used against them in military operations. I see this process extending over time, though. Probably another 20-25 years and in each stage it will go to lower and lower numbers. I think it is likely that we will see in the very near future, in the next couple of years, a treaty where both the US and Russia reduce to about 1,000 warheads each. Then down to hundreds, and that is when it really gets tough. I think it will take a decade or more to go from hundreds of nuclear weapons down to a regime where we could very favorably get to zero”.

“The sides are trying to achieve a couple of different things – one of which has to deal with nuclear disarmament, and really replacing the START treaty with something that will continue to serve as a real foundation for the relationship moving forward and for security moving forward,” he said.

But, he added, “there is also a need to work on rebuilding the relationship as such, rebuilding trust and confidence. And this is an exercise that is part of that. That’s possibly even more important than the numbers of warheads and the nuclear security issues themselves.”