Taiwan Wants to Know Why Indonesia Joined China in a Naval Exercise East of Taiwan

In a rare moment of diplomatic friction, Taiwan has called on the Indonesian government to clarify joint naval exercises with China that took place in waters east of Taiwan. 

The exercise took place on the morning of August 12, between 6:30 a.m. and 9:30 a.m. As part of the naval exercise, the Indonesian Navy frigate KRI I Gusti Ngurah Rai and the Chinese People’s Liberation Army Navy’s Honghe, a guided-missile frigate under the Eastern Theater Command, practiced maritime maneuvers. The drill included practicing formation, maritime communications, as well as replenishment-at-sea, and concluded with a divergence ceremony.

For its part, the Indonesian government has denied that the exercise was threatening in any way.

“The passing exercises are not war-fighting in nature, but rather a universal naval tradition conducted when passing through the waters of another country,” the Indonesian Navy said in a statement. It described passex activities in general – including, presumably, the one on August 12 – as “goodwill engagements that are commonly conducted by navies around the world as an expression of naval brotherhood and the maritime diplomacy associated with warships.” 

Similarly, the Chinese government claimed that the exercises were in the interests of “jointly safeguarding regional peace and stability.”

Certainly, the scale of the exercise is not to be overstated, as it only involved two vessels. At the same time, according to geointelligence firm ingeniSPACE in a report published by Domino Theory, the exercise took place in Taiwan’s exclusive economic zone (EEZ). The Indonesian vessel, which had its Automatic Identification System (AIS) on, first entered Taiwan’s EEZ before aligning with the Honghe, which did not have its AIS on – as is common for Chinese vessels operating in Taiwan’s EEZ. The Indonesian frigate later passed close to but did not enter Taiwan’s contiguous zone. 

Before its joint exercise with the Honghe, the I Gusti Ngurah Rai had participated in a bilateral exercise, the Orruda 2025, with the Russian navy in late July. After docking at Yokosuka Naval Base in Japan from August 1 to August 8, it later set out for the joint exercise with the PLAN. After that, the Indonesian vessel entered the Philippines’ EEZ and was expected to pass through Scarborough Shoal, a disputed reef claimed by both China and the Philippines. 

Some analysts have read the joint exercise as intended to hit out at increased maritime cooperation between the Philippines and Japan. The two countries held joint exercises with the United States at the end of July in the South China Sea. The drills took place not too long after a renewed round of confrontations between the Philippines and China around Scarborough Shoal, with Manila accusing China of firing water cannons at its vessels, while China hit out at the Philippines for what it claimed was an illegal blockade. 

The Philippines and Japan have increasingly set aside differences in the interests of maritime cooperation as of late. The two countries agreed in late May to delimit their overlapping EEZs and continental shelves in waters east of Taiwan. Such a move may have been aimed at strengthening Japan-Philippines cooperation in the event of a Taiwan contingency.

However, this area also partially overlaps with Taiwan’s EEZ, so Taiwan responded by asserting its own sovereign claims. While Taiwanese political leaders have praised the talks, Taiwan may not want to be left out of talks in which it could be a stakeholder. 

China also objected to the Japan-Philippines talks on the grounds of its claim to control Taiwan – and thus Taiwan’s EEZ. Beijing demanded that Japan and the Philippines “immediately cease all illegal acts that undermine China’s sovereign rights and interests” (referring to the maritime talks) and pledged to “to strengthen control and management over relevant waters.”

China’s joint exercise with Indonesia thus highlighted that the waters east of Taiwan are increasingly a focal point of cross-strait tensions. In June, the China Coast Guard stated that it had stepped up patrols in waters east of Taiwan as a response to the talks between Japan and the Philippines, a move that drew concern from Britain, France, Germany and the United States. China claimed these patrols were in the interests of law enforcement. 

Amid Typhoon Dolphin earlier this month, China’s Guangdong Maritime Safety Administration stated that it would enforce traffic controls on vessels heading northbound in the Taiwan Strait. The Taiwanese government responded by criticizing China for seeking to use the typhoon to reinforce its claims over traffic in the Taiwan Strait. Taiwan responded by issuing maritime safety notices through coastal radio and maritime safety centers to reaffirm that the Taiwan Strait is international waters. 

As for Indonesia’s apparent alignment with China in its joint exercise, it is unclear if this reflects a change in policy under the presidency of Prabowo Subianto. In many ways, such alignment would be ironic. Prabowo, previously a former general in Suharto’s New Order regime known for a long-standing record of human rights abuses before his later political career, had been accused in the past of fanning up anti-Chinese sentiment in Indonesia. Consequently, some see him as culpable for the 1998 anti-Chinese race riots that left over 1,000 dead. 

Nevertheless, Prabowo visited China as president-elect. He may be aiming to shed his anti-Chinese image in order to attract economic investment and pacify wary Chinese Indonesian voters domestically. Either way, China is a major economic force in Indonesia, operating factories, mines, and funding Belt and Road Initiative infrastructure projects. 

Prabowo has claimed that he aims to maintain ties of friendship with China, Japan, and the United States alike. However, if he were to rebalance to alignment with China, in many ways Prabowo would be charting the path previously taken by the Philippines’ previous president, Rodrigo Duterte. Amid mounting international criticisms of his bloody war on drugs – for which he is now being prosecuted by the International Criminal Court – Duterte increasingly lashed out at the United States and sought to bring the Philippines’ foreign policy into alignment with China. 

Such moves were later reversed when Ferdinand Marcos Jr. succeeded Duterte as president. Marcos pushed the Philippines back toward closer ties with the United States, as well as Japan. Marcos has also signaled greater interest in ties with Taiwan, congratulating President Lai Ching-te on his election victory in 2024 with a tweet. The Philippines has also made it clear that it sees itself as a stakeholder – or at least implicated – in a potential Taiwan contingency because of the over 150,000 Filipinos residing in Taiwan, mostly blue-collar migrant workers. 

In April, former Philippine Army Vice Commander Leodevic B. Guinid made headlines by stating that interoperability between the Taiwanese and the Philippine militaries would be necessary for evacuations to occur in the event of war. Certainly, a Taiwan contingency could potentially be a major political crisis for any Philippine political leadership, not only because of the economic and geopolitical impact from a distance, but because of the fate of the Filipino population in Taiwan.

Yet Indonesians are by far the largest Southeast Asian group in Taiwan and, in fact, the largest foreign nationality in Taiwan. It is believed that around 350,000 Indonesians reside in Taiwan, also mostly as blue-collar migrant workers. At the same time, there has not been much public discussion to date of what would happen to this group in the event of war in the Taiwan Strait.