As hard to believe as it may be, NK seems to think they can keep cranking things up because big brother China will back O down. As Chamberlain proved, you can create war by striving too hard for peace.
I was actually pretty impressed by the ROK/Japan/US response to this last attack. They told China to go pound sand regarding more talks with the DPKR and they have been agressively war gaming and building up forces in the region.
However, it may be too late to take a tough stance to the NORKs. The US/Japan/ROK have been playing Chamberlain with the DPRK for far too long and it looks like it may be time to pay the piper.
China would gain an immense amount of diplomatic and political credibility if they would shut down the Norks for good. If they played it right, they would be the good guys for getting rid of the idiots running the north, then stick the south with the bills for rebuilding the former DPRK.
0 is just radiating weakness and fear.