What the Royal Thai Navy’s Offshore Fire Support Reveals About Its Approach to Littoral Warfare

Why It Matters

Understanding Thailand’s approach reveals how small navies can influence regional security dynamics despite limited resources, emphasizing the importance of doctrine, inter‑service coordination, and civilian protection in littoral conflicts. This matters for policymakers and analysts tracking the rise of nuanced, status‑driven naval engagements in Southeast Asia’s contested coastal zones.

What the Royal Thai Navy’s Offshore Fire Support Reveals About Its Approach to Littoral Warfare

By Hadrien T. Saperstein

In December 2025, clashes along the Cambodia–Thailand border turned into open conflict for over a week, suspending the peace agreement brokered by Malaysia and the United States. Artillery, rockets, drones, and airstrikes turned rural districts into battlespaces. By mid‑month, at least twenty people were killed, hundreds wounded, and over half a million civilians displaced on both sides.

Although most of the fighting occurred on land, along the Chanthaburi–Trat front, the Royal Thai Navy launched Operation Trat Suppresses Foes. This operation consisted of a single patrol gunboat, HTMS Thepa, ordered to provide naval gunfire support from the Gulf of Thailand against fixed Cambodian positions ashore. Without the support of naval gunfire, it is unclear whether the detachment of Thai marines (RTMC) could have seized Ban Nong Ri even after it conducted a second concerted attempt to capture the area. A similar naval gunfire support mission took place last July during Operation Trat Strike 1, after Commander‑in‑Chief (CinC) Adm. Jirapol Wongwit (2024‑25) personally assumed command of a task force of four ships to help the marine element retake the Ban Chamrak area.

This article uses these campaigns to investigate what it means when a recognized small navy from Southeast Asia uses naval gunfire support from the “littorals” to assist land forces fight a border conflict.¹ The Thai case illuminates five points often underappreciated in the existing literature on the link between small navies, naval gunfire support, and littoral warfare.

First, the campaign reveals how littoral forces of small navies move along a continuum from peacetime constabulary tasks to combat roles without changing platforms, with greater fluidity than great‑power navies. A highly cited work on small navies by Michael Mulqueen, Deborah Sanders, and Ian Speller argues that what distinguishes small navies from great‑power fleets is not just less tonnage but their close attention to order of effect.² Analogously, Alexander Bergström and Charlotta Parrat’s study of littoral warfare highlights how the operational environment for small navies of coastal states differs from that of blue‑water fleets, with less attention given to ship‑on‑ship battle engagements, and how the same concepts can play out differently during naval gunfire support missions.³

Though the Thai navy remains attuned to the U.S. Navy’s surface way of warfare through its four decades of participation in Cooperation Afloat Readiness and Training (CARAT) and Cobra Gold exercises, it is a commonly held view inside the service that its Littoral Operations in a Contested Environment (LOCE) concept is not applicable to the Thai navy, as recently noted in a critical commentary by Captain Silp Panturangsri.⁴ Given Thailand’s current fleet force, the ships that can perform this role are limited: a very small number of frigates and offshore patrol vessels (OPVs), plus aging patrol gunboats to which HTMS Thepa belongs. This gunboat vessel is the same one that boarded Vietnamese trawlers illegally fishing in territorial waters only a few months ago, under the direction of Vice Adm. Apha Chapanon (2024‑25), Director of Maritime Security Area 1 (MECC‑A1), and is now delivering naval gunfire support into a neighboring state.

Second, the campaign reveals how small navies repurpose doctrine written for expeditionary amphibious operations for supporting forces engaged in border conflicts from littoral waters. Most navies, especially those of small states, do not address the problems of conducting naval operations in narrow seas and therefore lack a stand‑alone concept for littoral warfare.

This is only somewhat the case with the Thai navy. According to interviews conducted by the author with Royal Thai Navy officers, the service possesses a stand‑alone concept for naval gunfire support for land forces in the classified version of its Surface Combat Operations Manual (อทร. 3101). Though the manual’s contents cannot be confirmed, its understanding of naval gunfire support can be inferred from other sources, like the Surface Warfare Curriculum (see Appendix ค), which holds that surface and subsurface ships in coordination with coastal artillery do train to conduct Over‑the‑Horizon Targeting (OTH‑T) during land combat operations.

Yet, as its 2003 general maritime doctrine (อทร. 8001) reveals, the Thai navy can also draw on two decades of amphibious doctrine, courses, and exercises to further inform the conduct of naval gunfire support missions (see page 35). Doctrinally, since 2001, its amphibious warfare manual (Operations in Amphibious Warfare อทร. 3430) has framed coastal operations as joint sea–air–land campaigns in which naval gunfire support is central to enabling troops ashore. Following the adoption of the Network Centric Warfare Plan in 2015, the Fleet Training Command received permission to revise its training course on amphibious operations (Appendices C and D) in 2020 to improve its training for sailors planning specific phases from embarkation to landing and to ensure that it integrates its naval gunfire with air support and land logistics from other service branches.⁵ A new interpretation of its amphibious doctrine was issued in 2021 and then tested under the oversight of former Thai navy Commander‑in‑Chief (CinC) Adm. Chatchai Sriworakhan and RTMC CinC Adm. Sorakrai Sirikarn in a high‑profile beach‑landing exercise at Ban Thon, Narathiwat. It sought to validate both the updated amphibious doctrine and the 2020 force deployment guide (แนวทางการใช้กำลังของกองทัพเรือ พ.ศ. 2563). The effort to further integrate its amphibious forces with others has been followed up by bureaucratic reform inside the Thai navy in 2024, guided by the Bureaucratic 4.0 policy, leading to even greater inter‑service coordination during naval gunfire support missions.

Third, the campaign reveals how littoral warfare in Southeast Asia is inseparable from generating humanitarian risk. Milan Vego’s work on littoral warfare has highlighted how operations close to shore are not only inherently joint and tactically compressed but conducted in proximity to civilians and critical infrastructure.⁶

In the littoral waters across Southeast Asia, firing naval guns at targets just inland is sure to occur in a space crowded with villagers, roads, and border infrastructure. The Thai navy’s 2016 Operating Standards Manual includes guidance on controlling collateral damage by coordinating with coastal communities during both live‑fire training and active operations. For them, this is the real face of littoral war: older ships operating in the littorals with every round fired carrying not just explosive but legal and political weight.

Fourth, the campaign reveals how the concept of littoral warfare keeps evolving. Friedner Parrat’s longue‑durée study of Swedish coastal defence advances that coastal navies evolve as understandings of “what war is” change, shaped as much by shifting norms as by geography or technology.⁷ Small states enabled a novel norm around littoral warfare during the post‑Cold War era through the advent of international maritime law.⁸ Though their sea power still lies fundamentally in maintaining the guiding spirit of international law, small navies are now leading the charge to change normative behavior in littoral warfare through innovative naval technologies.⁹,¹⁰ This altogether affirms that sea power increasingly belongs to small navies of coastal states and not necessarily that of great‑power blue‑water navies.

The Thai navy is participating in the changing of norms around littoral warfare, acting on its long‑held desire to be a “leading” maritime security provider in its region and beyond since at least the late 2000s. This role was reaffirmed by former Defense Minister Sutin Klungsang at the 2024 Shangri‑La Dialogue, by chairing intergovernmental organizations tackling climate‑related security issues. The navy is not hesitant to deploy its sea power in littoral warfare when it believes its maritime interests are at stake, even if the operations have the potential to result in civilian casualties, like when hitting casino complexes.

Finally, the campaign reveals how navies can be motivated to participate in littoral operations not just in the pursuit of material benefits, as in assisting land forces acquire potential or claimed resources, but also by non‑material factors, such as rising nationalism or irredentism in domestic politics.¹¹ Small navies, even more so than great‑power navies, are driven by status‑seeking behavior, often at the expense of immediate material returns.¹² The concept of “amphibiosity” has been presented by the naval theorist Steven Paget to describe the way small navies invest in amphibious capabilities and rhetoric not only for operational reasons but as a way of enhancing their standing within national force structures and among partners.¹³

The Thai navy is no exception. It also regularly mobilizes fleet forces to participate in littoral warfare engagements to generate status enhancement. The service remains, like most navies, an organization eager to preserve a good image abroad, a factor that undergirded its construction of a maritime security establishment that accords with the standards of the Western international liberal order.¹⁴ The Master Plan under the 20‑Year National Strategy requires domestic agencies to pay close attention to Thailand’s positional status in international affairs (see page 9). Looking more broadly at Southeast Asia, this attention to non‑material factors has been missed in the debates on whether a naval arms race is currently underway in Southeast Asia.¹⁵ The special attention that small navies from Southeast Asia give to emerging technologies is likely linked more to the social “recognition” dilemma than to the classic “security” dilemma.¹⁶

The offshore fire support in Trat is more than a tactical vignette of the first and second Cambodia–Thailand conflicts of 2025. The engagement offers a concrete example of how a Southeast Asian small navy uses participation in littoral engagements to satisfy its state’s limited ends, all the while operating under doctrinal, political, and humanitarian constraints along a continuum from constabulary patrol to traditional naval gunfire support.

Hadrien T. Saperstein is a Ph.D. Scholar in International Relations from the London School of Economics and Political Science (LSE). His research bridges maritime strategic thought, international relations theory, and small navies from Southeast Asia. His articles on Thailand have previously appeared in Strife Journal, New Mandala, Asia Centre, Future Directions International, 9DashLine, and East Asia Forum. A forthcoming dissertation‑turned‑book that offers the first comprehensive history of the Royal Thai Navy is in the works.

References

1. On the definition and international law around littorals, see Prashant Kahlon. “War on the Coastline: Mitigating Civilian Harm in the Littorals.” Humanitarian Law & Policy. May 17, 2023.

2. Michael Mulqueen, Deborah Sanders, and Ian Speller. Small Navies: Strategy and Policy for Small Navies in War and Peace (London, UK: Routledge, 2014).

3. Alfred Bergström and Charlotta Parrat. “Two Perspectives on Littoral Warfare.” Defence Studies 22, No. 3 (2022): 433‑47.

4. Gregory Raymond. “Cobra Gold over Four Decades: Hedging, Alliances and a United States–Thailand Multilateral Military Exercise.” Contemporary Security Policy 46, No. 4 (2025): 781‑805.

5. Hadrien Saperstein. “The Royal Thai Navy’s Theoretical Application of the Maritime Hybrid Warfare Concept.” Asia Center. Oct. 12, 2020.

6. Milan Vego. “On Littoral Warfare.” Naval War College Review 68, No. 2, Art. 4 (Spring 2015): 30‑68.

7. Charlotta Parrat. “Swedish Coastal Defence Over Four Centuries: War as a Changing Institution of International Society.” Scandinavian Journal of Military Studies 5, Iss. 1 (2022): 350‑363.

8. Alred Hu and Jamese Oliver. “A Framework for Small Navy Theory: The 1982 U.N. Law of the Sea Convention.” Naval War College Review 41, No. 2 (1988): 37‑48.

9. John Hattendorf. “Sea Power and Sea Control in Contemporary Times.” Australian Naval Institute. Sep. 21, 2025.

10. Guntis Skunstiņš and Ieva Berzina. “Technological Maturity for Jeune École: The Case of Ukraine’s Naval Strategy.” Security & Defence Quarterly 52, No. 4 (2025): 1‑11.

11. Meghan Kleinsteiber. “Nationalism and Domestic Politics as Drivers of Maritime Conflict.” SAIS Review of International Affairs 33, No. 2 (Summer 2013): pp. 15‑19.

12. Anders Nielsen. “Why Small Navies Prefer Warfighting over Counter‑Piracy.” In Maritime Security: Counter‑Terrorism Lessons from Maritime Piracy and Narcotics Interdiction, eds. Edward Lucas et al. (Washington D.C., USA: NATO Emerging Security Challenges Division, 2020), pp. 97‑109.

13. Steven Paget. “Water Under the Bridge?—The Revival of New Zealand‑United States Maritime Cooperation.” Naval War College Review 74, No. 3, Art. 5 (Summer 2021): 41‑64.

14. Wissawas Koomrasi. “การขยายตัวของกรอบความร่วมมือระหว่างประเทศกับการบริหารจัดการความ มั่นคงทางทะเล: ศึกษาบทบาทของกองทัพเรือกับการจัดตั้งศูนย์อํานวยการรักษาผล ประโยชน์ของชาติทางทะเล [The Expansion of International Cooperation Frameworks in Maritime Security Management: A Study on the Role of the Royal Thai Navy in the Establishment of the Thai Maritime Enforcement Command Center].” Master’s Thesis (Bangkok, TH: Chulalongkorn University, 2023).

15. Kerrin Langer. “‘The Old World Fought, the Modern World Counts:’ Naval Armament Policies, Force Comparisons and International Status, 1889‑1922.” In Comparisons in Global Security Politics: Representing and Ordering the World, eds. Thomas Müller, Mathias Albert, Kerrin Langer (Bristol, UK: Bristol University Press, 2024), pp. 195‑215.

16. Joselyn Bart. “Emerging Technologies, Prestige Motivations, and the Dynamics of International Competition.” GoveranceAI (2022): 1‑56.