WASHINGTON: A diplomatic standoff between China and the Philippines that flared up two years ago in a dispute over fishing rights at a tiny shoal in the South China Sea is coming to a head after Manila decided to ignore Chinese threats and sue Beijing in an international tribunal.

The legal case marks the first time that an arbitration panel will examine China’s contentious, and oft-disputed, claims to most of the South China Sea, one of the world’s busiest byways for shipping and a potentially rich source of oil and natural gas.

The suit itself, a gargantuan, 4,000 page “memorial” filed before the Permanent Court of Arbitration in The Hague, amounts to what is basically an existential question about rocks. Or rather, it’s about the Philippines’ desire for scores of specks in the South China Sea to be officially classified by the international panel as rocks, rather than islands. On such arcane definitions can hang the fate of nations — or in this case, the extension of economic rights of states to the seas and seabed off their coasts.