[aussieguy1234]

That type of blockade is typically regarded as an act of war equal to dropping bombs. So that in itself could trigger a war.

[maxglute]

PRC-TW/ROC is already ongoing civil war that never ended in ratification, so legally it doesn't really matter. It's no different than ROC doing port closure policy for decades.

[Scarblac]

It is a way to fight the war that doesn't require amphibious landings.