When China signed the Hague Convention, it was ruled by the Qing Empire. The Qing Dynasty was overthrown in 1911, replaced by Republic of China. ROC itself was replaced by PRC on mainland in 1949, which is now the official government. China has not participated in this kangaroo court for over a 100 years. Trying to say PCA's decision is binding on China because the Qing Empire signed the convention more than a century ago is like saying British laws is still binding in United States today.
PRC explicitly said it would not recognize any unequal treaty at its founding in 1949. It did not "recognize" British rule in Hong Kong, but did not raising the issue when its military and economic strength were still weak. Britain was still one of the top world powers at the time, and it would be stupid for a newborn PRC to challenge it. Britain could bombard China's coast line into ruins and there wouldn't be a thing China could do at that time. That changed in the 1980's, and the British had to accept the new reality.
The PCA itself it outdated and unaffiliated with any UN organization. The UN has its own tribunals to arbitrate matters related to UNCLOS, which are the ICJ and ITLOS. The PCA rents the same building complex as ICJ, but otherwise is unrelated. Trying to paint it as "international tribunal" and "Hague court" is a laughable attempt to mislead the average Joe into thinking it has the authority to apply and rule on laws it has no jurisdiction over UN.
Well, PRC is actually a continuation of ROC and ROC itself is a continuation of Qing. The Qing emperor abdicated to the ROC, and PRC claims that Chiang violated Sun's three policies and thus PRC is not so much replacing Sun's China but replacing the illegitimate government of Chiang and thus a continuation.
If that were not the case China would have no claim on Tibet or xinjiang, to some degree north east China. No claim is wrong, it would be like Austro Hungary, the only thing that makes Austria, Austria is the Habsburgs, no one knows exactly what Austria should look like. So if PRC claims no precedent, then it won't know what the border is, since the last legitimate Han dynasty was Ming, yet PRC officially recognize 56 ethnicity, it's all very messy.
Another point, Mao can easily take HK, HK is not Taiwan, you can swim there, the battle hardened PRC troops can take HK with no more than a regiment if it came to it. Mao decided that if things turned to shit, he needed to be able to reach the West. Taiwan was obviously no go, so HK, being Chinese but not Chinese is the perfect location.
Whether China should listen to any organization was never the point. What was on trial wasn't SCS, it was China's ability to be a world power. That means being an Ahole when the situation calls for it.
OK time to finish you off.
https://pca-cpa.org/en/about/structure/members-of-the-court/
MEMBERS OF THE PERMANENT COURT OF ARBITRATION
https://pca-cpa.org/wp-content/uplo.../Current-List-Annex-1-MC-updated-20160719.pdf
Membership established conclusively
+
Still have not withdrawn membership in light of the ruling
= Major egg on face + butthurt
So where has the PRC established PCA is an unequal treaty/agreement/signing etc etc in any official statement or withdrawal of its representatives...in light of what I just posted above.
More:
https://pca-cpa.org/wp-content/uploads/sites/175/2016/01/2015-Annex-1-MC.pdf
Not the point of it all. I just seen a thread in Indian section about American decision on ISRO rockets, you will find if you actually manage to make something of India, Americans would be far less willing to help.
Keep in mind, 1989, may be what it is, but it isn't the worst in history nor has it not been surpassed. Yet the embargo is essentially only on us.
In 1989, Americans had our plane in their hands, it wasn't great, but they wanted to know what it was. They told us they were going to upgraded, instead they stripped it down and shipped it back to us. what's worse, they not only didn't upgrade it, they charged us for the shipping.
Did you know Americans also put tracking chips in all the blackhawks they sold to us.
Point is, come back to us in 10-20 years, and see if you still feel the same about international courts and their backers.