U.S. Deploys Stealth F-35s to the PH for Air Defense Drills

Washington has deployed for the first time one of its most lethal aircraft to the Philippines, the F-35, for air defense drills amid China's growing aggression in the South China Sea.

Observers view the aircraft's deployment for the second COPE Thunder drills—formally launched Monday at Clark Air Base in Pampanga and running through July 18—as a strategic move to reinforce deterrence, signal sustained regional commitment, and demonstrate power projection capabilities.

Around 2,500 personnel—2,300 from the Philippine Air Force (PAF) and 225 from the United States Pacific Air Forces (PACAF)—are participating in the exercises, which aim to facilitate bilateral fighter training with the Philippine Air Force, thus enhancing alliance readiness and combined interoperability among participating forces.

On the first day of the exercise, both PAF's FA-50 and PACAF's F-35 aircraft conducted a joint patrol exercise over the West Philippine Sea, Manila's name for the part of the South China Sea within the Philippines' exclusive economic zone (EEZ).

Lt. Col. Bryan Mussler, commander of PACAF's 421st Fighter Squadron, told reporters they chose the F-35 for the exercise to give another unit the opportunity to integrate with regional partners. "A free and open Indo-Pacific is something that we enjoy but should not take for granted in the future years if we want to continue to deter any form of aggression," Mussler said.

While the F-35 offers advanced capabilities, including sophisticated sensors, Mussler emphasized that the core of the drill is not just about technology, but about people and partnership.

"Our participation in the exercise has far less to do with the capability of the aircraft and far more to do with the people involved. The F-35 is the cornerstone of the US forces and we have a strong relationship with the PAF. We look forward to strengthening the alliance and continuing to integrate," Mussler noted.

Analysts say that with the F-35s capable of operating in contested airspace, China is likely to view their deployment as a threat and interpret it as confrontational posturing.

"On the deterrence issue, I believe that the F35s combined with joint exercises with regional allies are all geared to dissuade Beijing of its invasion plans. Given the just concluded simulated blockade of Taiwan and the continuous exercises of the PLAN carrier battle groups in the Western Pacific, I believe that the F35s sends a strong signal that the US is prepared to act in case of a Taiwan contingency," said Sherwin Ona, a visiting fellow at Taiwan's Institute for National Defence and Security Research.

Beijing considers Taiwan part of China and says it will use force if needed to take it back. The U.S. is Taiwan's strongest supporter, though it doesn't officially recognize the island as an independent country.

According to Ona, the presence of advanced MRFs in military exercises underscores the need to develop doctrines on interoperability and joint combat operations.

"The deployment of the F35 is a strategic move on the part of the US to strengthen its deterrence posture. It signals a continuing commitment to the region and shows the US ability to project its power," said Ona, also associate professor of political science at De La Salle University in Manila. "It will definitely benefit the PAF because of Manila's intentions to develop its own MRF program."

Ona explained that the F-35 could play a role in the Agile Combat Employment (ACE) doctrine, particularly with the presence of Enhanced Defense Cooperation Agreement (EDCA) sites in the country and the regular conduct of military exercises. "It demonstrates the ability to employ these assets in a combat environment, especially in the Indo-Pacific," Ona said.

Manila granted in 2023 the US access to four additional sites under EDCA, bringing the total to nine. The deal allows American troops to rotate and preposition material, equipment and supplies at designated locations across the country.

Dr Anita Abbott, chair of New Zealand based Asia Pacific Security Innovation Forum, said the stealth jets deployment shows that the US military posture is combat ready interoperability.

In other words, Abbott said the US is not only signalling China that the alliance is reinforced, and the message of deterrence is demonstrated, but also is ready to support its ally in deploying advanced stealth.

"The deployment demonstrates that the US is preparing for multi-domain conflict scenarios. Any contingencies from Taiwan Strait will spill over into the South China Sea. The Philippines certainly can be a partner for coordinated logistics and base operations,' Abbott said.

China claims most of the South China Sea, rejecting rival claims from other countries, including the Philippines, and a 2016 international ruling that its assertion over the waterway has no legal basis.

This month's iteration of the Cope Thunder exercise is the second of the year, following April's joint drills involving nearly 1,000 personnel and a deployment of F-16s – the same multirole jets Manila intends to acquire.

"We are testing our ability to respond across domains by shaping scenarios that simulate contested environments requiring flexibility, innovation and operational depth," Lt General Arthur Cordura, chief of the Philippine Air Force, said in his opening remarks.

Another expert, Abdul Rahman Yaacob, a research fellow at the Lowy Institute, said the deployment could align with the principles of Agile Combat Employment, noting that it would also enable the U.S. to assess what upgrades are needed at Philippine air bases to support future F-35 deployments.

"The F-35s and FA-50s have different capabilities and requirements. These exercises will enable the American and Filipinos to learn how they could operate side by side, but also how the different aircraft could complement each other in a joint operation," Rahman said, referring to how the deployment could advance interoperability with the Philippines.