One of the crucial accomplishments of the Philippines' assertive transparency campaign against China's gray zone activities has been the clarity it has brought to the situation around Second Thomas Shoal (known as Ayungin Shoal in the Philippines and Ren'ai Reef in China).

Thanks to Manila's 2023 campaign, the entire world has watched as China has thrown the entire gray zone tactics playbook at restricting access to the Philippines' outpost aboard the BRP Sierra Madre. They have visually documented incidents of swarming, blocking, laser-dazzling, bow-crossing, water-cannoning, going dark, spoofing, and (yesterday) ramming.

But why is this happening?

One central reason binds the rest together--China is aggressively enforcing a unilateral, undeclared blockade of the Philippines' outpost.

It's not new. Publicized incidents of China using force to block access to the shoal go back nearly a decade. It's just that until 2023 very few people discussed it--and pretty much nobody referred to it as a blockade.

Why not?

Beijing's motivation for not declaring a blockade is obvious. China is a gray zone actor, and as such it thrives when its activities are out of public view--obscured and deniable. Under the bright light of Manila's cameras, Beijing has been forced to explain itself.

Got that? The country that first seized, then built this massive military base at Mischief Reef just 30 kilometers away in the Philippines' internationally recognized exclusive economic zone (EEZ) ...

... now swarms, blocks, water cannons and rams these small wooden boats ...

... so that the Philippines can't make any repairs to this:

In other words, they're blockading the outpost.

As I've previously explained, China's blockade is part of a strategy of denial to force the Philippines to eventually abandon its decaying ship. This strategy has been largely successful, and there are increasing concerns that the Sierra Madre's days are numbered.

In the Philippines, the US and elsewhere, the reticence to use the b-word springs from worries over its implications. Isn't a blockade an act of war? What does that mean for the Mutual Defense Treaty? Shouldn't we just dial down the rhetoric?

But as Manila has concluded in launching its assertive transparency campaign, silence and murkiness have not served the Philippines' interests. Instead, they have allowed China room to consolidate its control over the West Philippine Sea at very little cost.

A country that carries out an illegal, aggressive, unilateral blockade against a smaller country's outpost--within that country's own EEZ--deserves to be treated as an outlaw and a pariah on the international stage.

Is it an "act of war"? Your mileage may vary. But it is absolutely an outrage and an act of high aggression, for which Beijing needs to pay a much higher price.

That begins when we call it by its name. 

It is a blockade.