China has been lashing out at rivals during the coronavirus pandemic, from a brutal brawl with Indian soldiers high in the Himalayas to a diplomatic war of words with Australia.
Now, Japan is firmly in its sights.
Just days ago Tokyo filed a formal diplomatic protest with Beijing over Chinese Coast Guard vessels violating the territory of the disputed Senkaku Islands for more than 65 consecutive days.
The vessels are still there, in an aggressive assertion of ownership by Beijing – one that is seemingly daring Tokyo to respond.
And China has just backed up that dare with a big stick by brazenly sending a submarine through waters close to the Japanese home islands.