if the north has weapons of mass destruction, which nobody doubts, why do they still have millions of soldiers? you don't need millions of soldiers when you have a nuclear deterrent to stop other countries from invading you... even america the superpower only has a few hundred thousand soldiers for occupying anything that is too valuable to be bombed
the whole purpose of the war in afghanistan is to dig a trench thru that country and lay an oil pipeline to export caspian oil and gas to pakistan... from there it gets sold by american companies to friendly places like south korea, japan, taiwan... sold for USA$ to friendly american allies who are good customers at buying american weapons and technology
this leaves the chinese out in the cold.. they have their own energy crisis as do the north koreans... they're spending way too much money building nuclear power plants and hydro dams while their factories are operating below capacity whenever they run low on power... they need oil too... cheap oil coupled with cheap political slave labour is what they need to take over all of american export markets
they can't very well walk into the middle east and start fighting america over the oil... they would just destroy each other and there's nothing to gain there...
what they can do is exercise their right to take over taiwan, push for regime change in north korea and install a puppet that will occupy south korea, and threaten the japanese so they won't allow america to use their island as an air base... and since china and korea have their own nukes the USA would have no choice but to fight a ground war... or compromise and let them have a cut of all that oil
the oil after all is worthless unless it can be brought to market and sold to someone who can pay for it