Amid rising tensions with China, the Philippines and the US have begun their largest-ever joint military exercises. The background is China’s territorial claims in the South China Sea and military maneuvers off Taiwan. For the first time, maneuvers with live ammunition will also be held in the South China Sea, which neighboring China claims almost completely for itself.

It is the first time that the Balikatan maneuvers will be held under the new Philippine President Ferdinand Marcos Jr. Marcos’ predecessor, Rodrigo Duterte, prioritized relations with China over those with the United States.

The background to the annual Balikatan exercises (roughly translated: shoulder to shoulder) is China’s territorial claims in the South China Sea and military maneuvers off Taiwan.

The focus should be on sea and coastal defense. During the maneuver, helicopters are to land on an island north of the main Philippine island of Luzon, which is about 300 kilometers from Taiwan. In addition, the recapture of an island is to be practiced using amphibious forces.

The training is intended to prepare the armed forces of both countries “to respond immediately and effectively to any situation, crisis or emergency under any circumstances,” said Philippine military chief Andres Centino at the beginning of the exercises. At the same time, they should contribute to peace in the Indo-Pacific.

In February, the Philippines had already promised the United States access to four more military bases in the island nation. US forces previously used five Philippine military bases.

A total of 17,600 soldiers are taking part this time, including 12,200 from the United States.

The maneuvers, which will also include sea combat exercises with live ammunition, will last until April 28.

Balikatan 2023 will be held in five provinces including Zambales and Palawan, which lie on the South China Sea. The Philippines and other countries are at odds with Beijing over sovereignty over resource-rich marine areas. China has created artificial islands to support claims and is unwilling to recognize an international arbitration award in favor of the Philippines. Another practice site is near Taiwan.

The timing of the military exercise is indeed delicate – however, China itself only ended its own three-day maneuver on Monday. However, Taipei again reported sightings of nine Chinese warships and 26 aircraft on Tuesday. According to Chinese information, the military exercises included the sealing off of the island and attacks on “key targets” located there.

Beijing regards the independently governed Taiwan as part of the People’s Republic and threatens to conquer it. In response to Taiwan’s President Tsai Ing-wen’s visit to the United States and her talks with the chairman of the American House of Representatives, Kevin McCarthy, China recently held large-scale maneuvers around Taiwan.

China warned that the Balikatan exercises should not meddle in disputes over contested waters. China’s territorial sovereignty, maritime rights and security interests should not be harmed either, said Foreign Ministry spokesman Wang Wenbin.