MANILA, Philippines – Two US carrier strike groups wrapped up joint drills in the Philippine Sea on Tuesday, June 23, in what some observers consider a show of force amid news of Chinese plans to enforce an air defense identification zone (ADIZ) over the South China Sea, which includes the West Philippine Sea.

The USS Theodore Roosevelt and USS Nimitz strike groups on Sunday, June 21, “began coordinated operations in international waters, demonstrating the United States’ unique capability to operate multiple carrier strike groups in close proximity,” said a statement from the commander of the US Pacific Fleet.

A third carrier strike group, that of the USS Ronald Reagan, was on a separate deployment in the Philippine Sea at the same time, the US Pacific Fleet said on its Facebook page.

The Philippine Sea is a vast area that spans the eastern coastlines of the Philippines, Taiwan, and Japan, all the way to the Mariana Islands including Guam, and Palau in the Caroline Islands. The US Navy typically skips mention of the precise whereabouts of its deployments.

The US has sent more frequent patrols in the Western Pacific as aggressive Chinese actions in the region increased, even after the onset of the coronavirus pandemic.

In the South China Sea, Chinese naval and militia vessels have continued harassing vessels from other claimant states, including Vietnam, Malaysia, and the Philippines.

A Chinese warship aimed its guns at a Philippine naval vessel in February, prompting Manila to file a diplomatic protest with the Chinese embassy.

On May 31, the South China Morning Post reported that Beijing plans to establish an ADIZ over the South China Sea covering the Paracel and Spratly Islands. The Philippines has a sovereignty claim over a portion of the Spratlys it calls the Kalayaan Island Group, including the civilian inhabited Pag-asa or Thitu Island.

An ADIZ would entail China requiring aircraft from other countries to identify themselves before entering the covered airspace, effectively exercising control over it.

With militarized installations built on top of what used to be submerged reefs in the West Philippine Sea, China has in recent years restricted the passage of Philippine aircraft and vessels. Philippine Air Force planes and Navy vessels are routinely challenged on radio by the Chinese when nearing these reclaimed outposts.

Radar stations on Zamora (Subi), Panganiban (Mischief), and Kagitingan (Fiery Cross) reefs mean the Chinese are able to watch air traffic above and navigation on the water. Missile installations on these features mean they are capable of striking aircraft and vessels they deem to be intruders.

China has an existing ADIZ over the East China Sea, covering an area it disputes with Japan.

With a hamstrung naval and air force still racing to modernize, the Philippines largely relies on a military alliance with the US for its external defense. The US in 2019 affirmed that its Mutual Defense Treaty with the Philippines covers the South China Sea.

Early in June, the US urged China to comply with the landmark 2016 Hague ruling that invalidated “excessive” Chinese claims of ownership in the South China Sea, and instead affirmed the Philippines’ sovereign rights to its exclusive economic zone on the water.

Vietnam, Malaysia, and Indonesia earlier made similar calls on China.

Around the same time, the Philippines paused the termination of its Visiting Forces Agreement (VFA) with the US, which President Rodrigo Duterte ordered terminated in February and would have lapsed in August.

With the VFA reinstated for the time being, American troops maintain their access to Philippine soil and waters. On Monday, June 22, Foreign Secretary Teodoro Locsin Jr said Duterte suspended the VFA’s repeal due to rising tensions in the South China Sea.

The US welcomed the move – an acknowledgment of America’s still key role in the Philippines’ defense and security profile.

US naval patrols in the Western Pacific, particularly in the South China Sea, have effectively enforced the Hague ruling by asserting international vessels’ right to innocent passage and belying China’s territorial claims, said former Supreme Court associate justice Antonio Carpio.

Such patrols, called “freedom of navigation and overflight operations” or FONOPs, are also the US’ way of maintaining dominance in the region faced with an increasingly controlling China.

“Our operations demonstrate the resilience and readiness of our naval force and are a powerful message of our commitment to regional security and stability as we protect the critically important rights, freedoms, and lawful uses of the sea for the benefit all nations,” said Rear Admiral James Kirk, commander of Carrier Strike Group 11 led by the Nimitz. – Rappler.com