The recent incident at the Scarborough (Panatag) shoal is no doubt the most brazen move thus far by the region's certified Biggest Bully – China – in the history of its escalating altercations with the Philippines over territory.

From news reports, it appears that the Philippine Navy's BRP Gregorio Del Pilar had discovered eight Chinese fishing vessels allegedly poaching large quantities of endangered marine species, including live sharks, at the shoal.

The resulting standoff – and our seeming inability to act decisively on a critical national security concern – further showed the vulnerabilities of the Philippines in a dispute over territory with an emergent world economic and military superpower.

But there are two ways of looking at the territorial dispute, which I will call the "thick" and the "thin" approaches. Our new baselines law, Republic Act 9522, classifies Panatag (Scarborough) Shoal as a regime of islands under Art. 121 of the Law of the Sea Convention (LOSC). Under LOSC, a regime of islands has its own territorial sea, Exclusive Economic Zone (EEZ) and Continental Shelf.

Obviously, RA 9522 assumes that the shoal is part of Philippine territory in the fullest sense of the term. From that perspective, the reckoning point therefore is the shoal as an island grafted into Philippine territory.

It is what I call the thick approach, precisely because the claim to be made from it is full sovereignty as understood in the national territory clause of the Constitution. Since it is a regime of islands, a case can well be made that what the Chinese fishing vessels did was violate its territorial sea, given the facts available to us. Given the shoal's classification under RA 9522, it would appear that the Chinese had violated its territorial sea, which extends from its coast up to a distance of 12 nautical miles.

The thin approach is what the Department of Foreign Affairs (DFA) has been saying all this time: that the Chinese violated our EEZ, reckoned from the base points off the coast of Zambales. From those points, the shoal, which is about 137 nautical miles away from Palauig town in the province, no doubt falls within the said maritime regime. This approach is so-called, because under the EEZ, the Philippines has "sovereign rights" to the marine resources found in the area, to the exclusion of all the others.

The regime of sovereign rights is not the same as full sovereignty. It is limited only to the economic exploitation of resources found in the shoal, subject to certain conditions, and cannot be equated with the full exercise of sovereignty control of every piece and bit of territory there in the concept of an owner. It is otherwise known as "protective jurisdiction."

But either way – thick or thin – we may now have a way to take China to compulsory arbitration with a final and binding judgment, which they have not been keen on doing.

The thin approach does not even require the Philippines to assert that the shoal is a regime of islands. The shoal may well be no more than rocks or coral reefs but even China recognizes that the area falls within the Philippine EEZ, except that it maintains that the Philippine claim to sovereign rights falls in the face of China's mainly historic title to the shoal (which is highly doubtful, from the point of view of contemporary international law, which generally dismisses historic title as ineffective).

What the DFA doesn't seem to realize, Prof. Harry Roque notes, is that the issues surrounding the shoal are different from those in the Spratlys.

Unlike issues involving the exercise of sovereign rights, which are subject to the compulsory jurisdiction of the International Tribunal on the Law of the Sea (ITLOS), conflicting claims to both maritime and land territory – as what obtains in the Spratlys – will require the consent of China to litigate.

"The point is," says Prof. Roque, "with the incursion of China in an undisputed maritime area under the sovereign right of the Philippines, we could avail of mandatory and compulsory jurisdiction of the UN's ITLOS, which we could not otherwise resort to in the case of the Spratlys." (To be continued)