So what, the tens of thousands of people protesting in the street, smashing Japanese cars and damaging Japanese companies' property is all sabre rattling?
I was more referring to the seriousness of the diplomatic situation behind the scenes. As in, it would never escalate into military action.
Perhaps this is not much different to the Falklands dispute. The country's claim is tenuous but the leader is forced to take it seriously for their own political benefit. And then the suffering population use it as an excuse to let off steam and express their hatred for the other country whilst also rallying behind their leader.