N.Korea says there will be war
They're pissed off at new UN sanctions imposed on them over their nuclear program. Theyre also pissed at US for beefing up their missile defense shield aimed at them saying N Korean missiles can hit Hawaii. They're always pissed at something. There has never been a peace treaty to end the last Korean War, just an armistice to stop the fighting.
The only thing that has kept them from attacking S Korea are all the nukes we have pointed at them in S Korea. The last time they attacked they lost their entire army and it took a million man army from China to save them.
It will be even worse this time.