Indonesia's reported acquisition of the BrahMos supersonic cruise missile is undoubtedly a significant boost to its coastal defence capabilities. It sends a clear signal that Jakarta is serious about strengthening deterrence in an increasingly contested maritime environment.
Yet there is a danger that the missile's impressive specifications overshadow a more fundamental reality: the BrahMos missiles alone are not a game changer for Indonesia’s defence strategy.
The appeal of BrahMos is easy to understand. With a range of up to 290 kilometres in its export version, supersonic speed, and proven anti-ship capability, it poses a credible threat to hostile surface combatants operating close to Indonesia's coastline. In a crisis, it would complicate an adversary's planning and increase the risks of naval operations in Indonesia's archipelago.
For a country seeking a cost-effective way to strengthen deterrence, the BrahMos represents a prudent investment. However, missiles alone do not deliver an effective deterrent. On their own, the BrahMos are vulnerable targets.
The BrahMos depends on radar, communications nodes and targeting systems to receive firing data. These supporting assets are often more vulnerable than the launchers themselves. Enemy aircraft, electronic warfare units or precision-guided munitions can disable radars or communications, rendering the missile batteries ineffective even if the launchers remain intact.
Mobility helps but is not sufficient. BrahMos launchers mounted on high-mobility vehicles can relocate after firing, making them harder to target. However, movement alone cannot protect them against continuous surveillance by satellites and drones. Without air defence, launchers remain at constant risk whenever they move, deploy or reload.
To realise its full operational potential, the BrahMos must be integrated within a broader system-of-systems architecture that combines surveillance, targeting, command and control, and air and maritime defence capabilities. This is critical for the Indonesian military to detect threats early and ensure the BrahMos's survival in a future conflict.
Thus, an effective defence strategy depends on an integrated sensor network to detect threats early. However, the Indonesian military currently lacks a complete picture of its air and maritime domains. This is where Indonesia's real capability gap lies.
Air & Maritime Coverage Gap
The first challenge is threat detection. The BrahMos system is not self-protecting, and its launch batteries are vulnerable to drone and missile attacks from an adversary's surface combatants, submarines, or aircraft. Without timely detection, warning and effective air defence, these launchers could be neutralised before they can engage their targets. The Houthis' activities in Yemen illustrate this vulnerability. Their anti-ship missile sites have repeatedly been targeted and destroyed by American air strikes, demonstrating that land-based anti-ship missile systems can themselves become high-value targets if they lack adequate protection and concealment.
The survivability of any future Indonesian Brahmos system, therefore, depends on the ability to detect incoming threats from the air and maritime domains early, providing enough warning to activate air and missile defences or relocate the launchers before they are targeted.
However, Indonesia's archipelagic geography presents an immense surveillance challenge. Stretching across more than 17,000 islands and covering over six million square kilometres of maritime territory, the challenge of ensuring sufficiently credible surveillance of the maritime and air domains is significant.
Currently, Indonesia's capabilities to detect potential threats from the maritime domain, especially from the subsurface, are lacking. In April this year, a suspected Chinese unmanned underwater vehicle (UUV) was found in Lombok Strait, a critical maritime chokepoint linking the Indian Ocean to the Pacific.
Several suspected Chinese UUVs have been previously found in Indonesian waters. In 2019 alone, two separate incidents were reported in February and March, whereby suspected Chinese UUVs were found near the northern tip of Bangka Island and the Riau Islands, respectively. A year later, another suspected Chinese UUV was found in the waters near South Sulawesi.
Similarly, Indonesia has gaps in its air-domain surveillance capabilities. Currently, the Indonesian military deploys 20 radar units, which is insufficient across the vast archipelago. Plans aim to increase this number to 30 by 2029, but it remains debatable whether these additional radars could provide complete coverage across the vast Indonesian archipelago.
Lack of Airborne Early Warning & Control
Indonesia's lack of airborne early warning & control (AEW&C) capability represents a critical gap in its air and maritime defence architecture. Ground-based radars are constrained by Earth's curvature, terrain, and the vast distances separating Indonesia's islands, limiting their ability to detect low-flying aircraft and sea-skimming cruise missiles at long range. An AEW&C aircraft overcomes these limitations by providing a high-altitude sensor capable of detecting threats hundreds of kilometres away, extending warning times and enabling commanders to coordinate a timely response.
This shortfall has direct implications for the survivability of high-value assets such as BrahMos launch batteries. Without persistent airborne surveillance, Indonesia may detect incoming threats too late to disperse launchers, activate air defence systems, or launch pre-emptive strikes. The absence of AEW also weakens the integration of air, naval, and ground forces, making it more difficult to build a common operating picture across Indonesia's vast maritime domain. In a conflict against a technologically advanced adversary, this would leave critical assets more vulnerable to surprise attacks and reduce the effectiveness of Indonesia's overall deterrence posture.
A Credible Air Defence System?
Detecting threats alone is insufficient. There must be a capability to destroy these threats once they have been detected. However, there are still gaps in Indonesia’s air defence capabilities to deal with any aerial threats once they are detected.
Currently, the Indonesian air defence system comprises various platforms from a broad range of suppliers: China (TD-2000 B and Type-90 35MM), Norway (NASAM-II), Poland (KOBRA), Switzerland (Skyshield-35) and the United Kingdom (Forceshield). Indonesia's air defence coverage remains heavily weighted towards short-range systems. Aside from the NASAMS II batteries deployed around Jakarta, the country's other air defence assets have only limited engagement ranges, leaving significant gaps in medium- and long-range air defence coverage.
Building a credible, layered air-defence system to protect the BrahMos is critical. A layered approach combines short-, medium-, and long-range air defence systems with radar, electronic warfare, and early warning assets to provide overlapping protection. This significantly enhances the survivability of the launch batteries, ensuring they remain operational long enough to deliver their intended deterrent effect.
The BrahMos is a potent weapon system, but on its own, it is not a game changer. Without layered air defence to shield its launch batteries from drones and precision strikes from the adversary’s cruise missiles, Indonesia risks fielding a capability that appears formidable on paper but proves vulnerable in combat. The real challenge, therefore, is not acquiring the BrahMos. It is building the integrated air defence architecture that allows the Brahmos to survive and fight.
