Our ally Japan is getting serious about defending themselves.
Apparently, North Korea and China don't seem so benign from Tokyo's perspective.
And the long supply lines to Middle East energy supplies run past China.
If Japan is worried about China's threats to Japan's oil supplies, Japan's rearmament is just beginning. Even a gretly strengthened Navy and Air Force that are limited to a thousand miles from Japan will do Japan no good if China wants to cut Japan's oil supplies from the source. Japan will need a navy with air power capable of projecting power all the way to the Arabian Sea.
In a generation or less, we will probably see Japanese aircraft carriers operating in the Indian Ocean again. And to support such far flung deployments, we will see Japanese bases from India to the South China Sea to perhaps Taiwan, too, I bet.
I would never change places with China. Every step China takes to increase their power projection capability runs into a country--no matter which way your go--that isn't happy about that and reacts by increasing their own power (Even Russia can act like a Chinese poodle for only so long until it recovers some power lost when the Soviet Union went belly up.). It is quite possible that net Chinese security is actually running backwards for every increase in absolute Chinese power.
Japan's decision to rearm will make our position in the western Pacific far more secure.