Let me try to draw a parallel between the Eastern and Western theatre. The EU seems to have some problems with Russia (in fact, we don't, but that's a different story), East and Southeast Asia seem to have problems with China. Both regions rely on the US to counter these two countries. Now, take away the US (more likely than you think) and the only one caught with its pants down are the Asian countries.
Why? The only capable country (technology, economy and manpower wise) in the East is Japan, the rest, in fact only Vietnam and Philippines are against China, are dirt poor and lack any technology. All these two countries have is low quality manpower.
The EU on the other hand has Germany, France, Italy and the Benelux (leave the US mole UK outside) with all the high-tech, economic and high quality manpower clout to build up a formidable military if there arises a need. That's why more and more people come to realize the need to get out of US-led NATO and form our own alliance, not to counter Russia but to form an even greater Eurasian economic zone spanning from Lisbon to Shanghai without the US being able to play dirty tricks.
Without the US, Japan is pretty much on its own and with a stagflationary economy going well into its third decade, I don't see anything positive for Japan in its future.