The North Koreans will not invade the south imo because:

1.) They are too weak to go on the offensive, they could only fight a defensive war and that'd be stupid and useless. they would be to quickly overrun by South Korean troops and their allies. (The NK best shot would have been during the 50's when the south was extremely weak)

2.) They need food, the majority of why their doing this is because theyre trying to intimadate the south into sending them food again, becasue theyre too prideful to ask for it.

3.) China wouldnt back them with military actions because of their trade with the USA. if the two countries decided to declare war, then the USA wouldnt have to pay back the trillions of dollars we owe, also we are their biggest trading partner. ontop of that each year the chinese take more and more steps to becoming a republic.

zen