Indonesia and China are at maritime loggerheads amid rising Chinese incursions into Indonesia's exclusive economic zone. Image: Twitter

An unprecedented Chinese protest over Indonesia drilling for natural gas in its own waters appears to have cast new light over why Jakarta remained strangely silent over a recent seven-week incursion by a Chinese research ship and two armed Coast Guard escorts.

Officials declined to comment on the report by the Reuters news agency, but they have made it clear through informal channels that, unlike neighboring Malaysia and Vietnam, Indonesia rejected the demand and ensured the drilling program was concluded on schedule.

Although the international and domestic media largely ignored the incursion at the time, the Indonesian government was clearly anxious to keep it that way and avoid a public diplomatic spat with a country with which it enjoys close economic ties.

But diplomats say staying silent implies Beijing has succeeded in enforcing its unilateral nine-dash line of territorial sovereignty that intrudes into Indonesia’s 200-mile economic exclusion zone (EEZ) and encompasses other proven offshore gas fields.

It is the first time Beijing has set out to pick a quarrel with Indonesia, which is not a claimant to the disputed Spratly Islands and has always maintained the nine-dash line is illegal under the United Nations Law of the Sea, meaning there is nothing to discuss.

China’s bullying behavior continues to puzzle observers, who wonder how long it will be before the Indonesian public and its often-fiery nationalists become more acquainted with events along its northern maritime border.

“China has a country here which is more inclined to temporizing,” says one senior Western diplomat familiar with the situation. “Yet it is doing everything it can to make it difficult for them. I don’t understand it.”

Quoting parliamentarians briefed on the issue, Reuters said the initial Chinese protest letter was followed by repeated demands for Indonesia to stop the drilling being carried out in the Tuna block by Harbour Energy, a joint venture between Premier Oil and state-owned Russian company Zarubezhneft.

The company has since reported promising results from the three-well appraisal program, but it is not clear whether it has been enough to expand proven reserves beyond the one trillion cubic feet mark that will firmly establish it as a commercial find.

A map of the area the incidents took place. Source: Twitter

Protest over military exercise

The Chinese are also reported to have sent a second letter protesting the largest-ever land exercise between Indonesia and the United States last August, which involved 4,500 troops and ranged across Sumatra, Kalimantan and Sulawesi.

China has never done that before either, despite the fact that the so-called Garuda Shield maneuvers have been conducted since 2009 and normally remain within Indonesian territorial waters and far from the South China Sea.

According to Muhammad Farhan, a National Democrat Party legislator on the House defense commission, the initial Chinese protest was made within days of a rented Malaysian exploration rig arriving at Tuna, about 20kms inside Indonesia’s EEZ, in late June.

An armed Chinese Coast Guard ship was already on the scene with China’s Foreign Ministry telling Reuters in response to recent questions that it was “carrying out normal patrol activities in waters under Chinese jurisdiction.”

Two months later, the 6,500-tonne research vessel Haiyang Dizhi 10 crossed the maritime border with its automatic identification system (AIS) activated and clearly making no secret of its presence close to the drilling operation.

Unknown to the Indonesians at the time, it was being escorted by an additional two coast guard cutters, which had been running dark since leaving their home base in Hainan to link up with the survey ship.

The Haiyang Dizhi 10 began steaming in a grid pattern about 110kms long and 10kms wide, indicating to experts that it was mapping the seabed using a common multi-beam echo-sounding system that forms a fan shape beneath a ship’s hull.

The search pattern appeared to be confined to a 15-20km-wide area just inside the EEZ where the rig was located, roughly conforming with what is now believed to be the extent of China’s vague nine-dash line, which broadens out further to the south in a large arc.

A China Coast Guard ship passes near an Indonesian warship in a July 2019 file photo. Photo: Indonesian Navy’s Western Region Fleet Command

Chinese naval presence

At that point, it appears to envelop Natuna D Alpha, the almost legendary 45 trillion cubic feet gas field, which was discovered in 1972 but has remained untapped because of dangerously-large quantities of Co2.

Over the first week of the Haiya Dizhi 10’s operations, fishermen reported sighting a Chinese destroyer and five other warships, apparently surveilling the aircraft carrier USS Carl Vinson, then about 80kms west of the drilling operation.

Apart from one quick dash to the Fiery Cross Reef for replenishment, the research ship remained on station for the next seven weeks, shadowed by up to nine Indonesian Navy and Maritime Security Agency patrol craft with orders not to intervene – something that apparently annoyed some senior naval officers.

The Haiyang Dizhi 10 finally pulled out of the area on October 22 – four days before the start of the Association of Southeast Nations (ASEAN) summit – and headed back to its homeport of Guangzhou, leaving one Coast Guard vessel behind.

Previously, Beijing had only sought to exert its traditional fishing rights inside the nine-dash line. But since 2016, when a Chinese Coast Guard ship seized back a captured trawler in Indonesian territorial waters around Natuna Island, there have been fewer incursions – until now.

Ship trackers say the bulk of the Chinese fishing fleet, along with its coast guard and militia escorts, have begun ranging further out into the Western Pacific in search of concentrations of fish before they reach Southeast Asian waters.