US quietly lowers threshold for conflict in the South China Sea

The US has been steadily ratcheting up the pressure on China's sea forces in a way that could lower the threshold for conflict in the South China Sea, already a hotbed of tension and dispute.

The US is signaling a tougher stance toward the Chinese maritime militia, a paramilitary sea force disguised as a fishing fleet and known to harass foreign rivals to enforce China's vast sovereignty claims in the contested waterway.

The Chinese maritime militia "thrives within the shadows of plausible deniability," according to Andrew Erickson, a leading expert at the US Naval War College, but it can no longer hide like it once could.

The Department of Defense first called attention to the maritime militia in its 2017 report on China's military power. The report explained that China uses its commercial fishing fleet to engage in gray-zone aggression, "to enforce maritime claims and advance its interests in ways that are calculated to fall below the threshold of provoking conflict."

(U.S. Navy photo by Mass Communication Specialist 2nd Class Declan Barnes)

It wasn't until this year, though, that the US really began putting pressure on the militia forces.

Chief of Naval Operations Adm. John Richardson warned his Chinese counterpart during a meeting in Beijing in January 2019 that the US Navy will treat coast guard and maritime militia vessels as combatants and respond to provocations the same way it would a Chinese navy ship, the Financial Times reported.

In March 2019, Secretary of State Mike Pompeo publicly assured the Philippines that the US would come to its defense in the event that it was attacked in the South China Sea. "Any armed attack," the secretary explained, "on Philippine forces, aircraft or public vessels in the South China Sea will trigger mutual defense obligations."

US Ambassador to the Philippines Sung Kim clarified the earlier assurances on June 14, 2019, telling reporters that US security guarantees apply to potential acts of aggression by the Chinese maritime militia.

"Any armed attack, I would think that would include government-sanctioned militias," the ambassador explained, according to The Philippine Star. He did not say what type of behavior would constitute an "armed attack."

The increased pressure is intended to change China's strategic calculus in the disputed waterway, experts argue.

Secretary of State Mike Pompeo.

"By injecting greater uncertainty about how the US will respond to China's grey-zone coercion," Bonnie Glaser, a China expert at the Center for Strategic and International Studies, told the Financial Times, "the US hopes to deter Chinese destabilizing maritime behaviour, including its reliance on coast guard and maritime militia vessels to intimidate its smaller neighbours."

At the same time, it potentially makes it easier for a lower-level dispute between China and its neighbors to escalate, especially considering the ambiguity surrounding both the US deterrence posture and the role of the maritime militia.

Incidents involving Chinese fishing vessels, potential members of the maritime militia, are frequent occurrences in the South China Sea. It is unclear exactly what kind of incident might trigger US defense obligations.

For instance, in April 2019, more than 200 Chinese fishing vessels allegedly swarmed Thitu Island, a Philippine-occupied territory in the Spratly Islands.

And, last week, a suspected Chinese vessel allegedly rammed a Philippine ship in the South China Sea, sinking it and then sailing off as nearly two dozen Filipino fishermen fought for their lives in open water.

China has denied allegations of misconduct.

This article originally appeared on Business Insider. Follow @BusinessInsider on Twitter.