In a few months, a former US president will probably be asked to travel to North Korea in pursuit of military denuclearisation. His name won't be George W. Bush, of course. It will be Jimmy Carter, or maybe Bill Clinton. Or one other person.
In 1994, Mr Carter did exactly that. Meeting personally the then North Korean leader Kim Il-sung in Pyongyang, he hammered out an understanding that was to lead to the 1994 Agreed Framework - negotiated later in Geneva.
The lead US negotiator in Geneva was top American diplomat Robert Gallucci. But that war-stopping agreement was achieved not simply because the US was so ably represented, but also because the basics of the accord had been spelled out in the Kim-Carter talks.
The key to the overall accord, therefore, was the top-down approach to diplomacy - the only approach that works with a dictatorship like North Korea.
In the current six-party negotiations in China, the US lead negotiator has been Christopher Hill. Indefatigable, precise and thoroughly schooled in the art of diplomacy, Mr Hill is as good a man for this sort of intellectual and diplomatic torture - that is, negotiating with North Korea - as you can get. Dr Gallucci himself would be the first to praise Mr Hill's efforts. But Mr Hill has had to operate, since 2005, under a handicap that Dr Gallucci did not face: the lack of a prior sign-off of the North Korean leader on the basic shape and conclusions of a negotiated deal. Instead of instructions going to the North Korean delegation from the top down, the North Korean negotiators have had to take their winnings from the negotiating table back to Pyongyang for approval.
There have been three problems with this bottom-up approach. First, even senior North Korean officials are afraid of showing independence or freedom of thought. This leads to the second problem. Kim Jong-il, the current boss of North Korea, is a very strange man. To make matters worse, he has been recovering from a severe medical setback, although no one is certain of his exact condition. That illness may help explain the constant wavering of the North Korean delegation in Beijing.
And, until recently, Pyongyang had officially been a member of the Bush administration's notorious list of governments that have supported terrorism. Thus, Mr Hill has had to negotiate with a government that his own boss had, in effect, said was not trustworthy - not ideal for progress-making, diplomatic give and take.
Mr Hill's role is now over; the world awaits the Obama administration for action. So the question remains: will the North Koreans ever abandon their nuclear-arms programme? The answer is 'yes', but only if: first, the price in aid is high enough and, second, some very high-level American travels to Pyongyang to nail down the framework of the deal.
The most obvious possibilities for this mission are Mr Carter or Mr Clinton - and the next US president, Barack Obama. This is the only way this deal will ever get done.
Tom Plate is a syndicated columnist and a member of the Pacific Council on International Policy