The NPT has two main purposes: to stop countries acquiring nuclear weapons and to get those who already have them to move to full nuclear disarmament. While it is true that the NPT has done a reasonable job in curtailing the spread of nuclear weapons to new countries, the fact remains that even after Start II there will be more nuclear weapons in existence than when the Treaty came into force in 1970.
Far from disarming, the UK and French governments are introducing new nuclear systems (the UK's Trident programme represents a significant enhancement of its nuclear capability), and their policy statements make it clear that while they do not want others to acquire nuclear arms, neither do they want to give up the prestige and imaginary security conferred by their own.
This state of affairs cannot go on. The non-proliferation regime is already under considerable strain (a situation exacerbated by the shortfall in funding for the International Atomic Energy Agency to carry out its safeguarding duties) and unless the nuclear states go into the NPT Conference in April with some very positive commitments it could start to unravel completely.
Surely the time is ripe to start negotiations for a worldwide ban on nuclear weapons in order to remove this scourge from our planet forever. The NPT should be extended initially for a limited period and concrete steps put into place in order to achieve its aim - a nuclear weapon-free world.