I wrote the following for ChinaFile:

My initial reaction is that the tribunal’s award overwhelmingly favors the Philippines—a huge win for Manila.

China’s only lawful claims in the South China Sea would be 12nm territorial seas from land features in the Spratly Islands deemed to be rocks above high tide. China cannot claim an Exclusive Economic Zone (EEZ) from any of the land features of the Spratlys Islands, including the largest, Itu Aba. Nor can it claim any historic rights to resources within the nine-dash line.

In particular, the tribunal ruled as follows:

• China cannot lawfully claim historic rights to resources within the nine-dash line.
• China (and others) cannot claim an EEZ from land features above high tide in the Spratlys, which were all judged to be “rocks” entitled only to a 12nm territorial sea.
• Mischief Reef was determined to be a low-tide elevation on the Philippines’ continental shelf. China’s construction of artificial installations on the reef violate the Philippines’ sovereign rights.
• The Spratly Islands as a group cannot generate any maritime zones as a unit. This appears to be an effort to pre-empt a Chinese claim to any maritime zones based on straight baselines that could be drawn around the Spratlys as a whole.

What does this mean? The only lawful claim to maritime zones that China can claim in the South China Sea would be a 12nm territorial sea from land features in the Spratly Island that are above high tide. China (and others) cannot claim an EEZ from any land feature in the Spratlys, as none were judged to be islands under UNCLOS warranting such a zone. China cannot claim any historic rights to resources, either, as the tribunal judged that China gave up those rights when it acceded to the convention. In this way, the tribunal’s ruling restricts significantly the scope of maritime claims that China can lawfully make under UNCLOS in the South China Sea. Paradoxically, this may further increase the importance that China attaches to its sovereignty claims over these land features.

• Finally, a few areas of the ruling favored China:
• Gaven/McKenna Reef was deemed to be a rock and not a low-tide elevation.
• The tribunal claimed no jurisdiction in the in stand-off over Second Thomas Shoal, as it concerned military activities exempted by Article 298.
• Traditional fishing rights for all states within the territorial sea of features in the Spraltys were apparently upheld, based on the finding that the Philippines had traditional fishing rights at Scarborough.
• The tribunal did not define what the nine-dash line might mean but only ruled on what it could not mean, namely, a claim to historic rights.