Hmmmmm...
Basically this is the South China Sea / West Philippine Sea.
Everybody wants a piece of it.
Most ASEAN (Association of Southeast Asian Nations) countries have a claim on it. ASEAN is like, hmmmmm... EU but Southeast Asian. It's set to be more integrated in the following years but that's another story.
Anyway, Philippines filed a case before an international tribunal disputing the claims of China over the area.
PHILIPPINES WON.
Philippines is a US ally.
The US strongly backed the Philippines in the case.
Obama wants the world to recognize the ruling and support Philippines' jurisdiction.
CHINA CANNOT ACCEPT THE RULING.
It might set a precedent to other ASEAN countries like Vietnam, Malaysia, etc. to filed a case against China to solidify their claims.
Basically, China has been building exploiting natural resources in the area.
They have also been building man-made islands in the area to strengthen their claims.
MAN-MADE ISLANDS ARE NOT COVERED BY THE UNCLOS or the UNITED NATIONS CONVENTION ON THE LAWS OF THE SEAS or something like that. It's the law/treaty that governs the use of the seas and oceans of our planet, okay. So China kinda found a loophole.
They've also been SHOOING for Southeast Asian fishermen from fishing over the area WHEN THESE POOR FISHERMEN HAVE BEEN FISHING THERE ALL THEIR LIVES.
This area is also rich in natural resources. China destroyed all these coral reefs to create man-made islands.
No coral reefs. No fish. No food. No livelihood, It goes on and on.
BASICALLY IT'S SO MESSY.
TOO MANY COUNTRIES INVOLVED.
But if you study China's evidence, you'd really rule in favor of Philippines in this one.
Its a very dangerous a sensitive issue between CHINA, PHILIPPINES, VIETNAM, BRUNEI, INDONESIA, etc.
If y'all been reading Asian news, the President of Indonesia recently sailed in the area with an effin' WARSHIP.