It is evident from the economic investments in China and general posture toward China that current Japanese leaders seek arrangements that enable it to avoid becoming an adversary of China while helping it become a militarily powerful nation.
There is no question that closer interaction with Russia and India on security matters in the context of overall Asian security will make China think twice about Japan's advanced military development, even if Japan decides to go nuclear.
No matter how irrational or powerful it may turn out to be in the future, China cannot afford directly to antagonize India on its southern flank and Russia up north, while posing mortal threats to Japan at the same time. I believe the strategy of the present crop of Japanese leaders is to have strong security relations with Russia and India, and a good useful military relationship with the United States and Australia.
If, however, Japan depends entirely on the U.S. -- which is no longer the U.S. of the Cold War days -- for its security, neither Russia nor India will criticize China for its stand vis-a-vis Japan.