China opened up a new front for South China Sea conflict this week when one of its coast guard vessels collided with an Indonesian coast guard ship in the process of towing a captured Chinese vessel alleged to be engaged in illegal fishing. In a remarkably direct and frank statement, Indonesia’s Foreign Minister protested China’s violation of the “sovereignty of Indonesia’s territorial waters.” China responded by saying its vessel did not “enter Indonesia’s territorial waters.”

So is this just a factual disagreement about the location of the incident? Hardly. In fact, this whole episode highlights the troubling nature of China’s controversial “Nine Dash Line” claim, revealing that this claim is essentially a gigantic Exclusive Economic Zone with sovereignty over living—and maybe non-living—resources in 80 percent of the South China Sea.

The coast guard clash took place within 200 nautical miles of Indonesia’s Natuna Islands, which means that it took place within Indonesia’s exclusive economic zone (EEZ)(China does not appear to dispute this fact). Under Article 56 of the United Nations Convention on the Law of the Sea (which counts both China and Indonesia as parties), Indonesia is entitled to “sovereign rights for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters” within its EEZ. Most nations, including the United States, assert the right to prevent illegal fishing (e.g. exploitation of living resources) within its EEZ. Indonesia has recently been exercising this authority aggressively by seizing and destroying fishing boats caught illegally fishing in their EEZ.

https://www.lawfareblog.com/nine-dash-line-super-sized-exclusive-economic-zone