On the sidelines of the G20 Summit in Argentina, the United States and China announced a ceasefire in their escalating trade war, a move that temporarily mollified markets.

But that truce has not extended into the South China Sea and adjacent waters, where the two powers are pitted in tit-for-tat antagonism that many fear could soon tilt towards conflict.

The South China Sea didn’t come up during the two leaders’ discussions, according to people familiar with the dialogue. This is likely due to the seemingly irreconcilable gulf between the two sides, both of which have stepped up their military maneuvers in the contested waters in recent months.

In fact, just before the Trump-Xi meeting in Argentina, the US conducted on November 28 its third Freedom of Navigation (FONOP) patrol in the Taiwan Straits since July this year.

The US Pacific Fleet spokesman, Lieutenant Commander Tim Gorman, described the maneuver as a demonstration of “the U.S. commitment to a free and open Indo-Pacific,” and vowed that the “US Navy will continue to fly, sail and operate anywhere international law allows.”

US President Donald Trump and Chinese President Xi Jinping attend the recent G20 summit in Buenos Aires. Photo: AFP / Yomiuri Shimbun
US President Donald Trump and Chinese President Xi Jinping attend the recent G20 summit in Buenos Aires. Photo: AFP / Yomiuri Shimbun

In response, China’s foreign ministry spokesman Geng Shuang urged Washington to “cautiously and appropriately handle the Taiwan issue, avoid damaging the peace and stability of the Taiwan Strait and China-US relations,” while warning against further deterioration in bilateral ties.

At the same time, the People’s Liberation Army (PLA) Navy also stepped up its patrols in the area. A senior Chinese military official, Dai Xu, a PLA Air Force Colonel Commandant, reportedly even called for attack on US warships in Chinese-claimed areas:

“If the US warships break into Chinese waters again, I suggest that two warships should be sent: one to stop it, and another one to ram it… In our territorial waters, we won’t allow US warships to create disturbance.”

Beyond the bellicose rhetoric, there are increasing structural tensions. As Song Zhongping, a China military expert, told the South China Morning Post on December 4, “China stresses its maritime interests in the waters, while the US attaches importance to freedom of navigation. These are different starting points and cannot be easily reconciled.”

In late November, the US conducted several military maneuvers in a major show of force, including two-carrier naval drills in the South China Sea involving USS Ronald Reagan and USS John C Stennis strike groups and their accompanying escort warships.

A US naval vessel in the South China Sea. Photo: Facebook
A US naval vessel in the South China Sea. Photo: Facebook

Days later, the Pentagon deployed two B-52 bombers near contested islands in the South China Sea, challenging China’s claim to the waters and skies around its artificially-built islands and features.

The bombers “participated in a routine training mission” in “the vicinity of the South China Sea,” according to a US Pacific Air Forces statement. “This recent mission is consistent with international law and United States’ long-standing commitment to a free and open Indo-Pacific,” the statement continued.

The Pentagon describes such deployment as part of its “Continuous Bomber Presence” missions in the contested waters of Asia, pushing back against any revisionist challenges to the Indo-Pacific status quo.

During the Halifax International Security Forum on November 17, US Navy Admiral Phil Davidson, the commander of US Indo-Pacific Command, rang alarms about China deploying a “Great Wall of SAMs [surface to air missiles]” in the South China Sea.

He warned that China’s deployment of missile systems to contested islands gives it “the potential to exert national control over international waters and airspace through which over three trillion dollars in goods travel every year.”

Warships and fighter jets of Chinese People's Liberation Army (PLA) Navy take part in a military display in the South China Sea on April 12, 2018. Photo: Reuters
Warships and fighter jets from China’s People’s Liberation Army (PLA) Navy take part in a military display in the South China Sea, April 12, 2018. Photo: Reuters

China’s overt militarization of the disputes, Davidson argued, “violat[es] the sovereignty of every other nation’s ability to fly, sail, and operate in accordance with international law,” and undermines the, “the right of all nations to trade, to communicate, to send their financial information, to send their communications through cables under the sea.”

For the first time, Washington has been openly pressing Beijing to halt further militarization of contested islands, dismissing Beijing’s explanation that the build-up is purely for self-defense purposes.

Buoyed by its rapidly developing naval capabilities, China seems determined to push the envelope.

Two recent studies have underscored China’s remarkable ability to close its military capability gap with the US. A recent Rand Corporation study warned Washington about China’s “extraordinarily quickly [catch up] by any reasonable historical standard.”

Another bipartisan study commissioned by the US Congress went so far as to warn that China could even emerge victorious in a potential military conflict in the South China Sea.

It’s no wonder then an increasingly confident China has more directly challenged America’s access operations in the area.

The USS Decatur, left, narrowly misses PRC Warship 170, which cut in front of it near Gaven Reef in the South China Sea on Sunday Sept 30. Photo: US Navy/ gCaptain
The USS Decatur (L) narrowly misses PRC Warship 170, which cut in front of it near Gaven Reef in the South China Sea on September 30, 2018. Photo: US Navy

In September, the US destroyer USS Decatur, which was conducting a FONOP within 12 nautical miles of China-occupied Gaven and Johnson reefs, was forced to change course when a Chinese warship came within a provocative 40 meters of it.

In early December, Taipei warned about “irregular patrols” by the PLA, which has deployed in a “routine” fashion a growing number of warships to the Taiwan Straits, right up to the middle of the 112-mile strait separating China’s mainland from Taiwan.

In the past, the PLA forces would mostly remain closer to Chinese shores.

Perturbed by China’s expanding military presence in the Straits, Taiwan’s defense ministry tried to reassure that it “effectively monitored the situations and movements around the Taiwan Strait by means of its air and naval mechanisms to ensure national security and regional stability.”

As one Taiwan military source told regional media, however, the situation is increasingly dire. “Each time the US sent warships through the Taiwan Strait, the PLA has also dispatched its fleets to track the US’ movements.”

That’s accentuating concerns that an emboldened PLA Navy and a self-perceived still-dominant US Pentagon are sleepwalking into a conflict at sea.