“For this reason, Yazhou Zhoukan said Japan has the ability to build its own nuclear bomb if it were to revise its postwar peace constitution”
And, they have that ability even if they DON’T revise their Constitution.
Self preservation is a supreme motivator.
There was a time where Japan could look at the United States as a close and trusted Ally, that they could count on IF things went South.
At the same time, China knew that the last thing that they wanted to do was start some crap with Japan, because they knew that we would take a very dim view of that.
Thanks to Obama, that is no longer the case.