Specious though the south china sea argument feels to us, Its entirely consistent with a long held vision of China and its sphere of influence. What rankles, is the extent to which the opposition to it, the open-seas sailing policy, is being taken by actors (the US, Australia) who chose otherwise to disregard mediation and international law in matters of their own spheres of influence: East Timor for instance. This is not whataboutism, its directly relevant, contradictory behaviour. The Chinese have a long standing stated claim to the spratleys (which btw, I think is entirely bogus) but in no sense simply emerged into a state of claiming them in recent times. The laws being used to push back, are entirely a product of the post-WWII polity, were an attempt to construct a legal mechanism to mediate between states, which is being (forcefully) applied here by some states, who choose to disregard the same legal basis when applied to cases of their own.
Lebensraum was a manufactured need of political expediency and an explicitly expansionist act. The South China Sea is not lebensraum, its open-fishing rights, and over-flight and sailing rights, and mineral rights. It's also a vision of a defensive ring.
You know, that domino theory we used to be sold about chinese expansionist policy in S.E. Asia? its being played in reverse: they need this barrier, because we are trying to re-apply opium war logic to opening chinese capital investment markets, and land in China...