In the pre-dawn haze of the Java Sea, the silhouette of a warship cut through the mist, its radar scanning the horizon as part of a multinational naval drill. Aboard, officers from across Southeast Asia watched intently, each measuring their fleet’s strength against their neighbors’. In 2025, the question of which nation commands the strongest navy is no longer just about fleet size, it’s about cutting-edge submarines, strategic alliances, and the ability to project power in contested waters. From Indonesia’s growing submarine fleet to Singapore’s high-tech warships and Vietnam’s missile-packed corvettes, the maritime balance in Southeast Asia is shifting faster than ever. But who truly reigns supreme?
Indonesia
In the strategic heart of Southeast Asia, Indonesia’s vast archipelago of over 17,000 islands necessitates a formidable naval presence to safeguard its territorial waters and assert its maritime sovereignty. Recognizing this imperative, the Indonesian Navy has embarked on an ambitious modernization journey, focusing on enhancing both its coastal defense and power projection capabilities.
A cornerstone of this modernization is the expansion of Indonesia’s submarine fleet. In October 2023, the Navy operated four submarines: KRI Cakra-401, KRI Nagapasa-403, KRI Ardadedali-404, and KRI Alugoro-405. Admiral Muhammad Ali, the Naval Chief of Staff, emphasized the goal to increase this number to 12, stating, “The ideal number of submarines to support our forces is 12. However, we are still considering the government’s budget.” This expansion aims to support underwater defense and deterrence capabilities.
Indonesia’s defense strategy includes forging international partnerships to enhance its naval capabilities. In January 2025, discussions with India focused on acquiring the BrahMos supersonic cruise missile, a joint Russian-Indian development. This procurement would significantly enhance Indonesia’s maritime strike capabilities. Talks with Japan have resumed regarding the joint development of naval vessels, reflecting a mutual interest in strengthening maritime security. Agreements with France aim to deepen defense cooperation, including the acquisition of Scorpène-class submarines, emphasize Indonesia’s commitment to modernizing its fleet.
The Indonesian Navy is also focusing on upgrading its surface fleet. Collaborations with international partners are underway to develop and acquire advanced frigates equipped with modern combat systems. These efforts aim to enhance Indonesia’s blue-water operational capabilities, ensuring the Navy can effectively project power and protect its maritime interests. Through these comprehensive modernization initiatives, Indonesia is steadfastly advancing toward a more robust and technologically advanced naval force, poised to address emerging maritime challenges and uphold its sovereignty in the region.
Singapore
In 2025, the Republic of Singapore Navy (RSN) exemplifies a strategic focus on technological superiority, operating a compact yet highly capable fleet that underscores quality over quantity. A significant milestone in the RSN’s modernization is the commissioning of the first two Invincible-class submarines, RSS Invincible and RSS Impeccable, in September 2024. These advanced diesel-electric submarines, built by Germany’s ThyssenKrupp Marine Systems, feature air-independent propulsion systems, allowing extended submerged operations. Notably, they are the first RSN submarines designed to accommodate female crew members, reflecting a progressive approach to inclusivity. Two additional submarines of this class, RSS Illustrious and RSS Inimitable, are slated for commissioning by 2028, further supporting Singapore’s undersea capabilities.
In a move towards autonomous maritime operations, the RSN has deployed domestically developed Maritime Security Unmanned Surface Vessels (MARSEC USVs) since January 2025. These 16.9-meter vessels, operated remotely by a two-person crew, are equipped with advanced navigation systems and armaments, including a 12.7-millimeter stabilized weapon system. They are tasked with patrolling the congested Singapore Strait, investigating, and interdicting suspicious vessels, thereby enhancing maritime security while allowing manned ships to undertake more complex missions.
Singapore’s commitment to maintaining a cutting-edge navy is further evidenced by plans to acquire two additional Invincible-class submarines, recognizing that the current fleet size is “not optimal” due to maintenance demands. The RSN is set to introduce Multi-Role Combat Vessels (MRCVs) to replace the aging Victory-class corvettes. The first MRCV is expected to be launched in late 2025, serving as a “mothership” for various unmanned platforms, thereby enhancing the navy’s operational flexibility and reach.
The RSN’s strategic doctrine emphasizes network-centric warfare, integrating advanced technologies across all platforms to ensure seamless communication and operational efficiency. This approach enables rapid response to emerging threats and emphasize Singapore’s focus on maintaining a qualitative edge in maritime defense. Through these initiatives, the RSN continues to exemplify a defense strategy that prioritizes technological innovation and operational excellence, ensuring robust maritime security in a complex regional environment.
Vietnam
In 2025, Vietnam’s strategic focus on modernizing its navy is evident through significant acquisitions and active participation in international maritime exercises, underscoring its commitment to coastal defense and regional stability. Vietnam has supported its undersea warfare capabilities by acquiring six Kilo-class submarines from Russia, enhancing its deterrence and coastal defense strategies. These submarines, known for their stealth and advanced weaponry, represent a significant leap in Vietnam’s naval modernization efforts.
The Vietnam People’s Navy (VPN) has also focused on enhancing its surface fleet. The VPN has integrated advanced missile systems into its arsenal, including the domestically produced P-5 Pyatyorka/Shaddock anti-ship missile, with an upgraded range of 550 km. Russia has delivered two K-300P Bastion-P coastal defense systems to Vietnam, utilizing the P-800 Oniks/Yakhont supersonic anti-ship missile with a range of 300 km.
Demonstrating its commitment to regional cooperation and operational readiness, the VPN actively participates in multinational naval exercises. In February 2025, Ship 09 of Brigade 171, Naval Region 2, represented Vietnam in the Komodo 2025 Multilateral Naval Exercise (MNEK-5) in Indonesia. This exercise, themed “Maritime Partnership for Peace and Stability,” involved approximately 3,000 naval personnel and 40 warships from 37 countries. Vietnam’s participation aimed to strengthen friendships, build mutual trust, and enhance coordination among participating navies in disaster management and humanitarian assistance. Through these concerted efforts, Vietnam continues to enhance its naval capabilities, focusing on coastal defense and deterrence to safeguard its maritime interests and contribute to regional peace and stability.
Thailand
In 2025, the Royal Thai Navy (RTN) is actively modernizing its fleet, blending legacy vessels with new acquisitions to enhance maritime security. The RTN is advancing plans to procure four high-performance frigates, each valued at approximately 17.5 billion baht, with funding allocated for fiscal years 2026 and 2027. In pursuit of this goal, Thailand is collaborating with international partners, including Turkey’s TAIS Shipyards, which is proposing designs based on the MİLGEM program, encompassing Ada-class corvettes and I-class frigates. The RTN aims to finalize the specifications for these new frigates between June and July 2025, marking a pivotal step in the selection process.
Thailand’s endeavor to acquire submarines has encountered challenges. A 2017 agreement to purchase a Chinese-made S26T Yuan-class submarine faced delays due to issues with the integration of German-made diesel engines. Despite these setbacks, the RTN is committed to advancing the project. Negotiations with China have progressed, with expectations to receive the first submarine within the next three years. Newly appointed Navy Chief Admiral Jirapol Wongwit emphasized the importance of this acquisition, stating that submarines are vital for enhancing the RTN’s operational capabilities.
In October 2024, the RTN selected Trakka Systems’ airborne surveillance technology to upgrade its maritime patrol capabilities. This advanced system is designed to improve the detection and monitoring of maritime activities, thereby strengthening coastal defense and contributing to regional maritime security. Through these strategic initiatives, the Royal Thai Navy is reinforcing its naval forces, balancing the integration of modern assets with existing platforms to effectively address contemporary maritime challenges. In 2025, the Philippines and Malaysia are actively advancing their naval capabilities to address maritime security challenges within their respective territorial waters.
Philippines: Advancing Naval Modernization
The Philippine Navy is undergoing significant modernization to enhance maritime security across its extensive archipelago. A notable development is the plan to acquire at least two submarines, marking a pivotal advancement in undersea warfare capabilities. This initiative is part of the final phase of the military’s modernization program, reflecting a strategic focus on strengthening defense mechanisms.
The Navy aims to expand its fleet of Acero-class patrol gunboats by procuring ten more vessels. This expansion is designed to support coastal patrol operations and enhance the protection of territorial waters. Financially, the Armed Forces of the Philippines (AFP) have allocated 51 billion pesos to the Navy for 2025, emphasizing the government’s commitment to naval modernization. However, it’s important to note that the overall modernization budget received guaranteed funding of 35 billion pesos, which is below the anticipated 50 billion pesos, indicating potential funding challenges.
Malaysia: Enhancing Naval Capabilities in Strategic Waters
The Royal Malaysian Navy (RMN) operates in the strategically vital Strait of Malacca and is actively upgrading its fleet to maintain maritime security. A recent advancement includes a contract with Systems Engineering & Assessment (SEA) to supply a Torpedo Launcher System (TLS), integral to the RMN’s modernization efforts. Despite these initiatives, the RMN’s readiness level was reported at 56.52% in the previous year, falling short of targets. In response, the RMN has been allocated 1.761 billion RM for operating expenses in 2025, reflecting an increase of 84.933 million RM from the prior year, aimed at addressing operational readiness and fleet maintenance.
The RMN is pursuing the “15-to-5” transformation program, aiming to streamline its fleet from 15 classes of ships to five, thereby reducing operational and maintenance costs. This restructuring is intended to optimize resource allocation and enhance operational efficiency. Through these concerted efforts, both the Philippines and Malaysia are striving to enhance their naval capabilities, ensuring robust maritime security and stability within their respective regions.
Factors to Consider:
Naval power in Southeast Asia is shaped by a mix of technology, geography, and strategic priorities. Singapore leads in technological advancement, with state-of-the-art warships and network-centric warfare capabilities. As one defense analyst noted, “Singapore may have a small fleet, but its technological edge makes it one of the most formidable navies in the region.” Meanwhile, Indonesia and Vietnam are rapidly modernizing, supporting both surface and submarine fleets.
Vietnam and Indonesia’s growing submarine forces serve as critical deterrents, with a Vietnamese naval officer stating, “Our submarines are our silent guardians, ensuring no one underestimates our resolve.” Indonesia’s vast archipelago demands a large and versatile navy, while Singapore, despite its small size, maintains a highly capable surface fleet to safeguard its strategic position. The ongoing South China Sea disputes continue to drive naval modernization across the region, with a regional security expert remarking, “Every nation bordering these contested waters understands that a strong navy is no longer a choice, it’s a necessity.”
End Note
Determining the “strongest” navy in Southeast Asia isn’t straightforward, as each country has distinct strengths. Indonesia boasts the largest fleet and is undergoing rapid modernization, while Singapore, though smaller, leads in technological sophistication. Vietnam and Malaysia are also strengthening their naval capabilities, driven by regional tensions, particularly in the South China Sea.
A regional security expert noted, “It’s not just about fleet size anymore, technology, strategy, and partnerships define naval power in today’s world.” The increasing naval buildup is further influenced by the presence of external powers like the United States and China, whose strategic interests and military posturing shape the region’s security landscape. As one military analyst put it, “Southeast Asia’s naval race isn’t just about rivalry, it’s about survival in an increasingly contested maritime domain.”
