Washington still considers North Korea a rogue state

The nearly complete collapse of North Korea's Communist economy in recent years has led to food shortages, starvation and widespread stagnation.

It is largely dependent on outside aid to feed its 22 million people.

Recent visitors to Pyongyang say that almost all the factories are idle and many fields empty.

And aid agencies estimate that thousands have died from famine in the last five years.

So it would make economic sense for Kim to enter into dialogue with other countries.

Many argue he has no option.

Rogue state

But Washington remains cautious. It sees North Korea as a rogue state, with nuclear ambitions and a missile capability that threatens world peace.

North Korea needs aid to feed its people

It may also be worried that North Korea is, at the same time, courting China and Russia and that all could be used to extract concessions from the others.

Internally, Kim will have his own concerns about this new period of rapproachment.

Even tinkering with just a little reform could spell the end of his regime.

He will be aware that if he is serious about changing his country's course - as Deng Xiaoping did for China 20 years ago - he will have to convince the population that he's the one to thank for any economic upturn rather than being to blame for not having acted sooner.

There has certainly been a change in atmosphere.

The mystery for Washington, among others, is whether it has also changed the nature of the North Korean threat.