The Koreans arent shabby, but they need to stay close to home. The Chinese are improving, but the Japanese are very high quality and have a far larger fleet than the UK fr example.
They could stop this in an afternoon. The French solution for the enviro-nazis worked, and had almost no repercussions for France.
Ditto for the Norks who torpedoed a Soth Korean ship.
A japanese sub could fix this at night, and vanish. No claims ever need be made. The far south latitutudes of the Pacific are horrendously dangerous. Alll kinds of accidents can happen.
For bonus theatric points, Japan could even direct the whaling fleet to help search for survivors in the water.
They could pick up the survivors and feed them whale meat. “It’s all we have”....
The inventors of Kabuki would certainly manage something spectacular.