[NJ_gent]

"As long as China let's them"

Beijing is well within range of North Korea's nuclear-capable Tae-po Dong II missiles. They know this, so they're very, very careful in how they deal with North Korea. Prior to the current nuclear crisis, China supported North Korea because it was a convenient distraction of US forces in the area. With the dawn of North Korea's almost certain rise to being a nuclear power, China is stuck in the uncomfortable position of providing support to a madman while trying ever so delicately to take his finger off the button.

China handled North Korea for quite a long time. Now that North Korea is beyond anyone's handling, they're keeping the current regime on a lifeline to avoid a scorched-Earth policy nuclear launch ("if I can't have it, nobody can!") while working back channels with defectors and current government members to get someone in power who's more stable and more controllable.

That's not to say that China wouldn't possibly let a bit of weaponry and manpower grow legs and walk over to North Korea's defense in the event of a US attack (of course, Beijing would know nothing about it and deny any allegation to the contrary).

[rodguy911]

If you wanted to get conspiratorial you could suggest that China now has defacto control over N. Korea and they are now shuffling the deck to get the same with S. Korea. But it is a complex situation over there, tough to sort out all the time.