They’ve just now figured it out?
No. The Jap Navy has been seriously building up for over a decade.
“They’ve just now figured it out?”
Agree. They should have figured it out 25 years ago...if not before then. I suspect, instead, that they knew, but figured the US would be around to defend them.
Now they see that the US has pretty much spent its military in Ukraine and is one Hypersonic barrage from leaving the Pacific Theater for good (as having to explain away the loss of a Carrier is literally impossible), that any hope for the US to come to Taiwan/Japan’s rescue is about over, so Japan now realizes that they’re on their own.
Better late then never, I guess.