Importantly, the ruling rejects China's claim to the nine-dash line. The Post's Simon Denyer reports:
China’s nine-dash line, a version of which first appeared on its maps in 1947, loops through the vast majority of the South China Sea, and Beijing uses it to claim sovereignty over almost all the islands, reefs and rocks in the South China Sea.
Read more about the Permanent Court of Arbitration's ruling here.
Here are five stories that help explain the situation in the South China Sea and the importance of the ruling.
Why the South China Sea is so important to the Philippines
One of the disputed areas in the South China Sea is the Scarborough Shoal, a rich fishing ground once considered a regional common among the sea's surrounding countries, including the Philippines.
A third of the residents of Masinloc have depended over the years on fishing for their livelihoods, said Mayor Desiree Edora. Scarborough Shoal, a half-day’s sail from shore, was a refuge from storms, a gathering place for fishermen from all over and a home to abundant grouper and giant clams. Now, the Chinese have barred foreign boats. It is like being thrown out of your own house, she said.
“We can’t replicate what Scarborough Shoal can provide,” she said.
China has been rapidly building man-made islands
Satellite images acquired by The Post in 2015 showed that China has continued to build islands in the South China Sea's Spratly Islands despite Beijing's claims that construction had been halted. The U.S. and its allies are concerned about military assets that have been deployed to the islands.
Photos taken as recently as Sept. 8 show extensive construction work on several of the islands, including Fiery Cross Reef, Subi Reef and Mischief Reef, to build airstrips, helipads, a radar dome and what looks like satellite communication facilities and a surveillance tower.
The United States has called on China to stop land reclamation efforts in the area known as the Spratly Islands.
The U.S. and China are at odds over the freedom of navigation
In May, a U.S. warship sailed within 12 miles of one China’s largest artificial islands, prompting China to deploy fighter jets over the South China Sea. It was the latest "freedom of navigation" operation conducted by the U.S.
The presence of the USS William P. Lawrence, an Arleigh Burke-class guided-missile destroyer, prompted the Chinese military to scramble three fighter jets that monitored the destroyer, along with three Chinese ships, until the American vessel left the area.
“This operation demonstrates, as President Obama has stated, that the United States will fly, sail, and operate wherever international law allows,” said Cmdr. Bill Urban, a Pentagon spokesman. “That is [as] true in the South China Sea as in other places around the globe.”
The U.S. military has returned to Philippine bases, angering China
The Philippines' relationship with China was further complicated this year when the island nation inked the Enhanced Defense Cooperation Agreement with the United States, allowing the U.S. military to build facilities at five Philippine bases.
China’s posture is bringing the Philippines and the United States back together. This year, the Philippines moved forward with the Enhanced Defense Cooperation Agreement, or EDCA, which allows the U.S. military to build facilities at five Philippine bases and is likely to mean more hardware at Subic Bay, which is now technically a commercial, not a military port.
That means U.S. and Chinese ships sailing in close proximity, deepening an already tense and dangerous standoff. For the Philippines, it raises tough questions about how the next administration should balance big powers while protecting Philippine sovereignty and fragile economic gains.
China rejects arbitration and has been lining up supporters
Well before the international tribunal in The Hague issued its ruling, Beijing rejected the arbitration and said it would ignore the court’s decision.
China also began lining up countries to support its stance over the sea, and it claims as many as 60 countries are siding with Beijing in the dispute.
The numbers are questionable, and the idea of gaining the support of distant, landlocked Niger in a dispute about the South China Sea could seem faintly ludicrous.
Yet China’s frantic efforts to rally support ahead of a ruling from an international tribunal in The Hague may not be as meaningless as they might seem. Cold, hard Chinese cash and what many see as American double standards are undermining efforts to build a unified global response to Beijing’s land reclamation activities in the disputed waters and employ international law to help resolve the issue.
The lure of Chinese money is having an impact in the Philippines, where President-elect Rodrigo Duterte has made wildly contradictory comments on the issue but has suggested some openness to bilateral negotiations — if China builds railways there.