Indonesia was reported to be among the countries that expressed interest in the Indo-Russian BrahMos supersonic cruise missile at the recent Dubai Air Show. Under its Minimum Essential Force program, Jakarta aims to improve air and sea denial capacities, with a primary focus on anti-ship and anti-submarine warfare in coastal waters.

The Indonesian military expansion is coming amid escalating tensions with China over a contested area around the Natuna Islands, which belong to the Southeast Asian country.

Missiles, frigates and subs

Jakarta’s arsenal of anti-ship missiles is already quite robust. It includes the French MM-38 and MM-40 Exocet, the Russian SSC-3 Styx and SS-N-26 Yakhont, and the Chinese C-802. BrahMos would be a pretty notable addition to Indonesia’s missile forces, as it is one of the world’s fastest anti-ship and land-attack cruise projectiles.

BrahMos can be fired from ships, submarines and ground-based platforms. A variant for the Su-30 MKI fighter is set to be tested for the first time, according to Indian media reports.

Frigates and submarines are the other two pillars of Indonesia’s planned sea denial architecture

Frigates and submarines are the other two pillars of Indonesia’s planned sea denial architecture. On October 30, the second of two Sigma 10514 PKR guided-missile frigates was delivered to Jakarta by local shipbuilder PT Pal and Dutch defense contractor Damen. The Sigma 10514 PKR frigate is a multi-role vessel that can be used for patrol missions in the country’s economic exclusive zone (EEZ), as well as for anti-air, anti-surface and anti-submarine warfare and maritime security.

The Indonesian navy has also delayed the decommissioning of its Ahmad Yani-class frigates. A number of them will be sent to the Natuna Sea before the deployment of Sigma 10514 PKR frigates is completed.

As well, Indonesia received a Type 209 Chang Bogo-class attack submarine in August. The first of three vessels ordered in 2011, it was built by South Korean defense firm DSME. Jakarta plans to construct a fleet of 10 to 12 multipurpose submarines capable of operating in shallow (“green”) and blue waters alike.

As far as air defense is concerned, Indonesia recently finalized the acquisition of a complete NASAMS medium-range air defense system from Norwegian manufacturer Kongsberg. The ground-based platform will have to be equipped with US-made Raytheon AIM-120 missiles.

Indonesia currently relies on short-range surface-to-air missiles like the Swiss-manufactured Oerlikon Skyshield system. NASAMS will be deployed to protect the country’s capital city, but it could also be stationed to defend military installations on the Natuna islands.

Changing posture

Indonesia is an archipelago nation of about 18,000 islands. In July, Jakarta renamed the northern portion of its EEZ in the South China Sea as “North Natuna Sea.” This move drew a harsh response from Beijing, which disputes Indonesian claims to the waters surrounding the Natuna Islands.

The Natunas do not fall within China’s “Nine Dash Line,” which delineates the Asian giant’s claims to the South China Sea. However, Beijing lays claim to waters north of these Indonesian islands. The area is a rich fishing ground and is believed to have abundant oil and natural gas reserves.

To counter Chinese territorial demands, the Indonesian government is building up air and naval facilities on the Natuna Islands. Last year, Indonesian Defence Minister Ryamizard Ryacudu said his country would ramp up defenses around the Natunas by deploying warships, F-16 fighters, surface-to-air missiles, drones and a radar. In support of military activities on the Natunas, the Indonesian air force has also proposed developing an air base on Batam island, 20 kilometers off Singapore’s southern coast.

Susi Pudjiastuti, Indonesia’s maritime affairs and fisheries minister, said last month that her country would have to reinforce naval defenses against illegal fishing by foreign-flagged ships. Poaching cases in Natuna waters have multiplied in recent years. Notably, the constant presence of Chinese fishing boats, supported by their country’s coast guard, has strained relations between Indonesia and the Asian powerhouse – Jakarta and Beijing had three naval skirmishes last year.

Indonesia has maintained a low profile in the South China Sea until recently. Now, while Vietnam and the Philippines have softened their opposition to Chinese territorial demands (which have also been rejected by an international tribunal), Jakarta has become more assertive in safeguarding its maritime interests.

The Indonesian military build-up in the region bordering the South China Sea can be viewed mostly as geopolitical posturing. Jakarta wants to send a message to Beijing that it will defend its sovereign rights. But only strategic cooperation with regional and non-regional actors wary of China’s military expansion will give teeth to Jakarta to face Chinese pressure on the (North) Natuna Sea.