A plane with no weapons circled near some islands and dipped a toe into a tiny sliver of Japanese airspace - over water - in a single pass. Check the map.

China is full of shit about it being unintentional, they've been playing grey zone games for quite a few years now and the nations around them have caught on.

Your intellectual insight is to claim that this flight path was entirely designed around that one pass entering Japanese airspace? Perhaps you can share your spy recordings where they say, "surely this is how we will advance our cause".

I'd argue missile deployment is exactly proportional to an unplanned breach of airspace by a military asset.

That flight path with a toe dip into airspace over ocean vs. missiles designed to carry nukes. Do you not understand the difference between offensive nuclear weapons and maybe hearing a plane flying offshore?

It's historically a pretty good idea to build up your defense when a neighbor is brandishing their military on your borders

Are you afraid of that plane and its flight path? You're using language as if it is a weapon and threat.