That's not actually true. Taiwan agrees with China, because China's claims are simply those that successive Chinese governments held throughout the 20th Century. The United States used to agree with China - that is, until China went from being the ROC to the PRC.
As for what China is actively doing to assert these claims, I suggest you look at a map of which countries occupy which islands in the South China Sea. The PRC is not the worst offender there, by a long shot. Nobody's hands are clean in the matter.
Self-interested motivations (TW) or transitory diplomatic policies aside, I mean that it is plainly a bullshit claim. "We're big and we want it really bad" is not a justifiable standard of resolving resource and territory disputes.
Let's compare island occupation to island-building, island militarization and bullying tactics with vessels. Whatever combination of ways different parties are jostling over trying to de facto claim parts of the Sea, a pretty thorny root of the problem is one actor trying to claim all the marbles.
> island militarization and bullying tactics with vessels
Like sailing warships or flying military aircraft next to islands that a foreign country claims as its own? US military actions is the South China Sea could be viewed as highly provocative. I can see why China would respond by putting anti-aircraft batteries on the islands.
> Self-interested motivations (TW)
Everyone's motivations are self-interested. Virtually all countries bordering the South China Sea stake wide-ranging claims.
> "We're big and we want it really bad" is not a justifiable standard of resolving resource and territory disputes.
Of course, that's not how China makes its case. It claims that the islands have belonged to China for hundreds of years, and points to various old maps, historical use by Chinese fishermen, mentions in various treaties, and so on. I don't know how strong these claims are, but I try not to get worked up about tiny uninhabited islands. I mostly hope that the situation doesn't escalate, but many sides are capable of escalation - the US, China, the Philippines, Vietnam, and others.
> a pretty thorny root of the problem is one actor trying to claim all the marbles.
Two actors "claim all the marbles" (the ROC and PRC), Vietnam and the Philippines each claim 80% of the marbles, and Malaysia claims 30% of the marbles.
My original question was why any of this is relevant. If we're going to be raising random accusations against various governments, I can think of much more serious issues than some uninhabited islands and rocks, like the illegal invasion of Iraq or the overthrow of the Libyan government.
> It claims that the islands have belonged to China for hundreds of years, and points to various old maps, historical use by Chinese fishermen, mentions in various treaties, and so on.
> I mostly hope that the situation doesn't escalate, but many sides are capable of escalation - the US, China, the Philippines, Vietnam, and others.
Only one of those countries has been building / extending artificially reefs / islands in this area.
Xi lost face over this decision, and just said "tough, we aren't going to abide by it anyway". Hardly the actions of a reasonable government as good world citizens.
> I can think of much more serious issues than some uninhabited islands and rocks
China has deemed it very, very important to seize this area. It's pretty clear why to most people.
> US military actions is the South China Sea could be viewed as highly provocative. I can see why China would respond by putting anti-aircraft batteries on the islands.
You think it's reasonable to respond to freedom of navigation operations (also conducted by other countries than the USA) by militarising islands that aren't even theirs?
> "... the tribunal rejected China’s argument that it enjoys historic rights over most of the South China Sea. "
China doesn't recognize the tribunal's jurisdiction in this case, since China previously opted out of binding arbitration on territorial issues, as allowed by UNCLOS.
> Only one of those countries has been building / extending artificially reefs / islands in this area.
At the same time, the US has been conducting provocative military maneuvers in the South China Sea. These days, China and the Philippines are cooperating to some extent in the South China Sea. The US has been prodding the Philippines to take a more confrontational approach.
> China has deemed it very, very important to seize this area.
I think there are two issues. They view the sea as strategically important, and don't want to be at the mercy of the US Navy, which could shut down a lot of Chinese trade in the event of a conflict. They also don't want to lose face, and giving in to US demands that they drop China's traditional territorial claims would not go over well among the Chinese population.
> You think it's reasonable to respond to freedom of navigation operations (also conducted by other countries than the USA) by militarising islands that aren't even theirs?
"Freedom of navigation operations" is a propagandistic name given by the US Navy to very provocative military maneuvers in what China views as its territorial waters. I think it's entirely understandable that China puts defensive weaponry on islands it considers its own, in response to perceived violations of its sovereignty by a hostile military.
If they're not international waters, but rather the territorial waters of another country, then it's illegal. These are provocative maneuvers, meant to forcibly contest the territorial claims of another country.
> One can only speculate as to why that is.
Calling people shills is against the rules here. That's why you're not coming out and saying it, but rather trying to imply it.