The one potentialy good/game changing thing that COULD come out of this is a remilitarized Japan. They could very well determine that the US security umbrella is not dependable enough to ensure no reoccurance of a nuclear “man made event.” Both North Korea and China could well find that they have created a potential monster that changes (or at least seriously alters) the balance of power in the region.
I would imagine that our increasingly feckless President is doing nothing other than vicariously encouraging this move on Japan’s part.
With Japan’s technology and industrial base they could have serious deterrent capability in a very short space of time – changing their constitution would be the most problematic issue – but do-able if their citizenry feel genuinely threatened.