The sinking is a big deal, but "Sea of fire"-type shrieks from the DPRK make for a weird kind of morning ritual for those nuts --sort of you and me stretching out, or making some toast and coffee.
The sinking is a big deal. This is their way of demanding money. My guess is that the latest bag of loot from the PRC was substantially lighter than the DPRK's had been expecting.
Next step: They start proliferating LIKE CRAZY, while Obama talks realllllly sternly and does NOTHING. Then SK will begin major new efforts towards SDI & inquires about heavier AEGIS purchases. And Japan will announce stepped-up dev of their own advanced stealth aircraft.
Then a major arms race in Asia speeds up and all Taiwanese begin to sweat.
If it's the Mitsubishi that I'm thinking of, it appears to be a joint project with Northrop. Looks like an XF-23, but scaled down a bit. Much of the development is therefore complete.