North Korea threatens "final destruction" of South Korea

What kind of military intervention on a grand scale are you suggesting? If not nuking and not conventional warfare ("Iraq") then what?
China, yes, I said myself that China can and will act. But the UN? USA? How?

And yes, I know that if they don't, the UN can fold and Iran can run free. Unfortunately I fear that that is exactly what will happen.

But, we shall have to wait and see. Hopefully North Korea can be deterred.

War without the use of WMDs. When I talked about Iraq, I was not referring to conventional warfare because much of Iraq was not conventional. The original goal of Iraq seemed to be to achieve a regime change from that of Saddam Hussein. This part of the war was won fairly quickly, but the real problem was the insurgency (which is anything but conventional) that occured after. That is just one of many reasons why you can't really use Iraq as a model for what we should do if this situation with N. Korea arises.

It really comes down to China. If China takes strong action, then the U.N. and U.S. do not have to do as much. A nice naval blockade to block all imports and exports and military strikes on both IBM sites or nuclear development facilities could also do the trick.

Again, I do not have all the answers. I am just trying to point out that these things situations are very complicated. There are a lot more options than 1) pull an Iraq, 2) nuke them, or 3) let them do what they want.