On Thursday, Taiwan sent an unspecified number of fighters to warn away 39 planes from the Chinese People’s Liberation Army Air Force that entered its southeastern air defense zone.

At the same time, Taipei also detected three Chinese warships near its maritime waters.

China has been conducting exercises around the self-ruled island since August when the outgoing speaker of the US House of Representatives, Nancy Pelosi, made an overnight pit stop in Taiwan during an Asian swing.

China has been constantly testing Taiwan’s readiness to defend its sovereignty and territorial integrity.

However, there were instances when the Chinese warplanes entered the Philippine air defense zone when they flew to test Taiwan’s readiness to respond to intrusions.

For instance, 21 fighters, four bombers and a dozen other aircraft flew over the Bashi channel in northern Luzon, a strategic waterway between Y’Ami island, the northernmost Philippine island, and Taiwan’s Orchid island. Both the Philippines and Taiwan claim the important waterway as part of their respective 200-nautical-mile exclusive economic zones or EEZs.

Bashi Channel is a recognized international strait that allows innocent passage and overflight but these Chinese aircraft could have also strayed into the country’s airspace.

While Taiwan quickly responded to intrusions in its air defense zone, the Philippines never reacted, exposing its air defense weakness. It showed the Philippines has very limited capability to respond to external threats.

For nearly a decade, the Philippines has upgraded its air defense radar to detect intrusions into its air defense identification zone (ADIZ), putting up three radars in the western part of the country from northern Luzon, on Lubang Island, and in Palawan.

However, the air force still lacked fighters to intercept and stop aircraft straying into the country’s airspace. The Philippines can detect intrusions but it has no capability to stop and intercept unidentified aircraft.

For instance, there had been reported sightings of unidentified flying objects in Pangasinan, which some suspected to have come from China.

The military spokesman, Col. Medel Aguilar, said the armed forces were still validating the report. If the aircraft had hostile intentions, it already caused damage to the country.

The military cannot say if the aircraft in the Pangasinan airspace was commercial or military. It cannot even scramble an aircraft in Bashi Channel to challenge Chinese fighters and bombers.

The Air Force rarely scramble jets to intercept unidentified aircraft because it has only four or five FA-50 light fighters. These light fighters cannot match the much faster Chinese multi-role, air superiority fighters, Chengdu J10 and J20.

South Korea has delivered 12 FA-50s as trainer aircraft to prepare pilots to operate supersonic multi-role fighters like the F16 but the contract did not include after-sales service, like maintenance and spare parts. Thus, some of the aircraft were grounded.

No wonder the Philippines could not scramble aircraft to stop intrusions into its air defense zones.

Under the military’s modernization program, it envisioned an integrated air defense system that includes radar, fighters, and air defense missiles. The Philippines used to rely on the United States when the 13th Air Force was still operating from Clark Air Base.

When it abandoned its base in 1992, the Philippines was left without a credible air defense capability.

It is slowly developing an air defense capability. It has set up radars and has acquired Israeli air defense missiles but does not multi-role fighters. The United States has offered to sell 12 F6 fighters for $2.4 billion but the air force is keen on getting the Swedish Gripen fighters because they cost less. The Philippines has only $1.2 billion for the fighter program,

Sweden also promised to deliver the planes by 2024 while Lockheed cannot commit delivery of its F16s until 2030. It is uncertain if Sweden can match the US offer to deliver a complete package that includes training and after-sales service.

The Philippines urgently needs a multi-role fighter capability to complete its air defense capability. But it has to select a contractor that can promise to deliver a complete package at an affordable cost.

The F16 is a dream aircraft for the air force but the cost is beyond reach. The US, as a long-time military ally, can help the Philippines acquire the multi-role fighters by offering to shoulder parts of the cost under the annual Foreign Military Sales program.

The Philippines may have the lion’s share in military funding in the Indo-Pacific region but the military aid allocated to the Middle East and Pakistan dwarfed the amount given to the country.

Egypt, Israel, Jordan, and Pakistan get a combined $3 billion in military aid. The Philippines only gets a little over $100 million when Washington has refocused its security to the region as China’s influence and military capabilities continue to grow.

The intrusions into the country’s airspace and maritime borders show the country’s national security weakness. It has to invest more and take advantage of its alliance and security partnerships with other countries, like Australia, Canada, Japan, and the European Union, including France and Germany.

The QUAD (Australia, India, Japan, and the United States) mechanism can help monitor Chinese activities in the West Philippines Sea through its satellite sharing program, which US Vice President Kamala Harris promised last month.

The Philippines continued to be the weakest chain in the imaginary line of defense in the Indo-Pacific region. But the Philippines can be a reliable security partner if it has a modest, credible defense capability to help preserve the status quo in the region.