Brunei Security Report — March 21, 2026

Security analysis based on open-source intelligence and web research. Period: March 14 — March 21, 2026.

Executive Summary

Brunei Darussalam maintains a stable and low-threat security environment, characterized by proactive defense modernization and deepening strategic partnerships. The sultanate’s defense budget surged by 31.6% to approximately $594 million, reflecting heightened attention to maritime security and intelligence capabilities in the context of South China Sea dynamics. The 50th anniversary of Singapore-Brunei defense relations in January 2026 reinforced the country’s most important bilateral military partnership, while the renewed UK-Brunei Garrison Agreement ensures the continued presence of British Gurkha forces. Brunei continues to balance its security interests between traditional Western partnerships and its significant economic relationship with China, maintaining its characteristically quiet diplomatic posture.

Defense Modernization

Budget Increase

Brunei has increased its defense budget by 31.6% for the current fiscal year, bringing the total allocation to approximately $594 million. This exponential increase reflects the sultanate’s recognition of evolving security challenges in the South China Sea and broader Indo-Pacific region, and marks one of the most significant defense spending increases among ASEAN member states in percentage terms.

Air Force Modernization

The Royal Brunei Air Force (RBAirF) has focused on fleet modernization during 2025-2026:

• C295MW Tactical Transport Aircraft: Integration of the new Airbus C295MW fleet is underway, replacing aging platforms to improve strategic airlift and maritime patrol range. These aircraft provide a dual capability for troop transport and maritime surveillance over Brunei’s extensive EEZ.
• H145M Helicopters: Six Airbus H145M helicopters ordered in May 2024 are replacing the decommissioned BO105 fleet. These multi-role helicopters will enhance troop deployment capabilities and provide close air support.

Maritime & Intelligence Capabilities

The Ministry of Defence and Royal Brunei Armed Forces are actively working to improve intelligence, surveillance, target acquisition and reconnaissance (ISTAR) capabilities. Particular attention is focused on detecting and monitoring underwater threats to ensure effective response in maintaining Brunei’s territorial integrity — a direct response to the increasing complexity of submarine operations in the South China Sea.

Strategic Partnerships

Singapore Defense Relations (50th Anniversary)

The year 2026 marks the 50th anniversary of formal defense relations between Singapore and Brunei, making this one of the most enduring bilateral defense partnerships in Southeast Asia. During the 11th Defence Policy Dialogue held on February 5, 2026, defense officials reviewed a Milestone Update on Defence Relations and reaffirmed their commitment to further bilateral cooperation in areas of mutual interest.

The Singapore-Brunei defense relationship includes joint exercises, training exchanges, and Singapore Armed Forces training facilities in Brunei’s extensive jungle and maritime environments. This partnership provides Brunei with access to Singapore’s advanced military capabilities and training infrastructure.

United Kingdom Garrison

The UK-Brunei Garrison Agreement, renewed in December 2024, secures the permanent presence of a British Army battalion — the Royal Gurkha Rifles — in Seria. This arrangement, dating back to Brunei’s independence in 1984, represents one of the UK’s few remaining permanent military deployments east of Suez and provides Brunei with a security guarantee that extends beyond the capabilities of its own armed forces.

The British military presence also provides the Royal Brunei Armed Forces with regular access to joint training with a NATO-standard military force, enhancing interoperability and professional development.

ASEAN Defense Cooperation

Brunei participates actively in ASEAN defense cooperation mechanisms, including the ASEAN Defence Ministers’ Meeting (ADMM) and ADMM-Plus forums. As a small state, Brunei benefits from the multilateral security architecture these mechanisms provide, complementing its bilateral partnerships.

Maritime Security & South China Sea

Territorial Claims

Brunei maintains claims to maritime areas in the South China Sea that overlap with China’s expansive “nine-dash line” assertion. Unlike other claimants such as the Philippines and Vietnam, Brunei has adopted an extremely quiet diplomatic posture regarding its claims, avoiding public confrontation with Beijing while maintaining its legal position.

Energy Security

Brunei’s economy remains heavily dependent on oil and gas production, much of it from offshore fields in waters that could be affected by South China Sea disputes. The defense modernization program, particularly investments in maritime surveillance and ISTAR capabilities, is directly linked to protecting these vital economic interests.

Piracy and Maritime Crime

The waters around Brunei, particularly in the Sulu-Sulawesi maritime corridor to the east, experience periodic security concerns related to piracy and armed robbery at sea. While Brunei’s immediate maritime environment is relatively secure, regional maritime crime trends require ongoing vigilance.

Internal Security

Political Stability

Brunei’s absolute monarchy under Sultan Hassanal Bolkiah provides political stability, though it also limits civil liberties and political participation. The sultanate has been ruled by the same monarch since 1967, making it one of the world’s longest-reigning heads of state. Succession planning — with Crown Prince Al-Muhtadee Billah increasingly involved in governance — provides continuity.

Counter-Terrorism

While Brunei has not experienced a significant terrorist attack, the country maintains vigilance against radicalization. Its position in the broader Malay-Muslim world and proximity to areas affected by Islamist militancy in the southern Philippines and Indonesia necessitates continued counter-terrorism awareness and cooperation with regional partners.

Cybersecurity

As Brunei pursues its Vision 2035 digital transformation agenda, cybersecurity becomes an increasing priority. The country’s small but growing digital infrastructure requires protection against both criminal and state-sponsored cyber threats.

Economic Security

Diversification Imperative

Brunei’s dependence on hydrocarbons remains the primary economic security concern. The Brunei Vision 2035 aims to diversify the economy, but progress has been gradual. Oil and gas revenues continue to underpin government spending, including the expanded defense budget, making global energy price fluctuations a direct national security variable.

Chinese Investment

China has become an increasingly important economic partner for Brunei, with investments in refining, petrochemicals, and infrastructure. The Hengyi refinery on Pulau Muara Besar represents one of the largest foreign investments in Brunei’s history. This economic relationship adds complexity to Brunei’s management of its South China Sea claims.

Outlook & Assessment

Threat Level: Low

Brunei’s security threat level is assessed as Low, reflecting:

1. A stable internal political environment under the sultanate’s governance
2. Strong bilateral security partnerships with the UK and Singapore providing deterrence
3. No active armed threats or significant internal security challenges
4. Low crime rates and effective domestic security services

The primary watch areas are the evolving South China Sea dynamics and the longer-term challenge of economic diversification. The significant defense budget increase signals the sultanate’s recognition that maintaining a low threat level requires continued investment in deterrent capabilities, particularly in the maritime and intelligence domains.