Almost four years after multinational negotiations began to end North Korea's nuclear proliferation, the process is finally under way; promised fuel oil has been delivered by South Korea, the nuclear reactor at the heart of the crisis has apparently been shut down and UN inspectors are in place to verify the claim and ensure that the facility can no longer be used to produce plutonium for weapons. The moves are naturally welcome, but there can be no celebration until Pyongyang's atomic programme has been scrapped, its arsenal destroyed and the Korean peninsula declared nuclear-free. Given the wrangling to produce an agreement, punctuated by the North last October testing its first nuclear device and a months-long row over a frozen bank account in Macau, attaining those goals will not come easily. Six-nation talks resuming on Wednesday in Beijing must therefore be taken with the utmost seriousness by all sides so that a major threat to regional stability can be erased. Enticing North Korea to take the necessary steps will have a hefty price tag. In the deal signed in February, Pyongyang agreed to close the reactor at Yongbyon if it received 50,000 tonnes of fuel oil. There was also the proviso that a further 950,000 tonnes, or the equivalent value in aid, plus diplomatic benefits and security guarantees would follow if it declared all nuclear programmes and disabled facilities. While the initial steps now being taken were carefully thought through, no clear strategy was developed as to how subsequently to proceed. Shutting down Yongbyon cuts off the source of the North's bomb-making material; it does not, however, do anything about the estimated five to 12 bombs that the nation is believed to possess. It does not tackle concerns about uranium enrichment, another means to make atomic arms, or the missiles capable of carrying nuclear warheads. Then there are the wider matters - that the North is still technically at war with South Korea and the US and has the world's fourth-biggest army poised for action. Animosity with Japan remains strong. The atomic weapons are the North's bargaining chips. They will not be easily given up, if at all. But in light of the security threat they pose, the nations involved in negotiating for their removal - China, the US, Japan, South Korea and Russia - must put every effort into creating the right conditions to convince the North that destroying them is in its interests. While tough deal-making lies ahead, the basis for an agreement is clear: bringing North Korea out of its secretive shell and ushering it into the wider world. This will be achieved through economic and diplomatic means. Time and again, Pyongyang has indicated that it is willing to make such moves only on its own terms, and this will surely continue to be the case when it comes to nuclear decommissioning. The four years of six-party talks to get that process under way is proof enough of the arduous road ahead. While the North would seem to hold all the cards, it is also in its interests to strike a deal. The UN's World Food Programme estimates that one-third to half of the nation's 23 million people do not have enough to eat and in March it said that this year there would be a 20 per cent shortfall in the country's food needs. North Korea will not easily abandon its nuclear weapons. But with strong incentives to do so and the promise that the first phase of that process can be achieved with the mothballing of the Yongbyon reactor, there is more room for optimism than in the past. All the nations involved, however, must continue to work hard to end one of the main causes of instability for East Asia - no matter how long it takes.