Both of the nations I mentioned have reasons to fear Japan, but Japan has more reasons to fear them right now. The big question is when will Japan decide to join the nuke club. They make the decision to do so they will be operational within 6 months. China may be good at copying other people's stuff, but Japan can make this happen on its own.
And seeing the United States is now showing leadership at this moment, this is a wise act on the Japanese.
Japan's Latest Destroyer Sure Looks Like An Aircraft Carrier
Japan has inducted into service its largest warship since WWII, the 814 foot long Izumo. The activation of such a large ship, dubbed a 'Helicopter Destroyer,' has regional powers and academics alike questioning the limits of Article 9 in Japan's Constitution.
Clearly the Izumo, which is about the size of Italy's new Aircraft Carrier Cavour, is an aircraft carrier itself. Seeing that aircraft carriers are widely considered offensive weapons, something Japan's own constitution prohibits, this ship, and even its smaller Hyuga Class Helicopter Destroyer cousins, may be proof that Japan is moving back to an expeditionary military posture.
Japan's change is defense posture, although subtle (at least as subtle as slowly building larger and larger aircraft carriers while still calling them destroyers can be), is not unusual in the region as China has grown much more brazen and brash when it comes claiming, and even building, territory in the region.
As a result of China's growing dominance, a military arms race is gaining speed in the region. This movement has been even more charged as China gains more and more unique technological capabilities that will help it make good on its various territorial claims in the future.
Japan's own major dispute with China surrounds the uninhabited but strategic Senkaku Islands. This has resulted in intense diplomatic tensions between the two nations, as well as overlapping and conflicting air identification zones and nearly continuous aerial intercepts as a result, which also come at a great financial cost.
Having an aircraft carrier to project power in a region that is becoming increasingly volatile is not such a bad idea, but the Japanese Maritime Self Defense Force will shy away from saying that the Izumo is an aircraft carrier at all. They say it will primarily be used for anti-submarine warfare and disaster relief. It can certainly do those missions and do them well, but you don't build this big of a flattop to for hunt submarines around a few Destroyers, Frigates and logistical ships while on deployment.
There is no reason the Izumo cannot deploy dozens of JGSDF AH-64D Apache attack helicopters, heavy and medium assault helicopters or even the F-35B Joint Strike Fighter one day. Seeing as Japan already has the F-35A on order, and there have been no claims saying the Izumo's design precludes it from accepting the short takeoff and vertical landing version of the Joint Strike Fighter in the future, it remains a real possibility.
Aside from possibly signalling a departure from Japan's core self defense principals that were ratified post World War II, the fielding of Izumo and her yet to be delivered sister ship, is just one of many signals that underline the fact that the Pacific Theater increases in geopolitical volatility by the day. As a result, major powers are putting their money where their insecurities lay in order to deter future aggression and to provide a way to respond to territorial threats should that deterrence fail.