The Japanese non-aircraft carrier carriers got China’s attention fast. They also have copies of our Burkes. Japan could go nuclear very fast too.
Japan is capable of building hundreds of nukes with very accurate delivery systems in extremely short order.
Also, Japan has been invited to join the 5Eyes intelligence group.
About the length of time it would take to get the tools out and do the assembly !
Watching some analysts a few years ago and the moderator asked one how long would it take for Japan to develop a nuclear weapon - the response was: "oh, about 72 hours".
I suspect that they already have.