• Upholding a rule-based order amid great power rivalries 

In the 21st Century, the Indian Ocean Region (IOR) has emerged as one of the most strategically significant geopolitical spaces in the world. Stretching from the eastern coast of Africa to the western shores of Australia, the Indian Ocean serves simultaneously as a conduit for global trade, a theatre of strategic competition, and a platform for multilateral cooperation. At the heart of its stability lies the concept of a rules-based order a framework of international laws, norms, and established practices designed to ensure predictability, respect for sovereignty, the freedom of navigation, and the peaceful resolution of disputes.

A rules-based order refers to a system of international governance grounded in treaties, conventions, and multilateral institutions. In the maritime domain, the United Nations Convention on the Law of the Sea (UNCLOS) provides the foundational legal framework, defining maritime zones, navigational rights, and dispute resolution mechanisms. The central principle is that collective rules rather than unilateral power should regulate access to and use of global commons. Given that a substantial proportion of the world’s oil shipments and commercial trade transit through the Indian Ocean, the preservation of such an order is indispensable for both strategic stability and economic security.

The outbreak of the 2026 Middle East conflict between Israel, the US and Iran has underscored how distant wars can reverberate across the Indian Ocean. A US submarine torpedoed the Iranian frigate IRIS Dena off the coast of Sri Lanka in March, a dramatic escalation that brought the war into the Indian Ocean and saw the loss of dozens of sailors while raising serious questions about the safety of key shipping lanes and the resilience of the regional security framework. This incident, coupled with broader disruptions to energy routes and freight logistics stemming from the crisis in the Strait of Hormuz, illustrates the mounting pressure placed upon the rules-based system by intensifying great-power competition and interstate conflict.

India’s expanding maritime role 

Long perceived as peripheral to the broader Indo-Pacific strategic shift, the Indian Ocean has increasingly become a central arena of geopolitical contestation. India, in particular, has emphasised that the Indian Ocean is no longer passive, highlighting expanded naval deployments and sustained efforts to secure sea lines of communication (SLOCs). These SLOCs carry approximately 90 per cent of India’s trade and 80% of its energy imports, underscoring the direct linkage between maritime security and national economic resilience.

India’s activities including anti-piracy patrols, naval diplomacy, joint exercises, and maritime capacity building initiatives reflect both security imperatives and strategic ambition. By positioning itself as a net security provider, New Delhi seeks not only to safeguard its interests but also to reinforce regional norms aligned with a rules-based maritime order.

China’s expanding footprint and normative challenges

China has steadily expanded its presence in the IOR through infrastructure investment, diplomatic engagement, and maritime deployments linked to the Belt and Road Initiative. Port developments, logistical agreements, and increasing naval patrols reflect a strategy that blends economic outreach with strategic positioning.

There is concern about large fishing and research ships, sometimes funded by their governments that mix civilian and strategic activities. This can break usual maritime rules and make it harder to enforce international law, causing tension in the region. Smaller littoral states face complex choices in this environment. Decisions regarding port access and research vessel permissions reflect a delicate balancing act between economic opportunity, sovereignty, and adherence to international maritime standards.

China’s expanding strategic presence also raises diplomatic concerns. Despite reservations expressed by India and the US regarding the potential intelligence gathering role of Chinese research vessels, Sri Lanka has adopted a cautious, case-by-case approach following its 2024 moratorium rather than fully lifting the restrictions. Developments in 2026 including selective approvals for foreign vessels while broader policy frameworks remain under review highlight the complex balancing act that smaller littoral states face between economic engagement and maritime security concerns.

Regional responses: Cooperation under strain

In response to evolving strategic dynamics, India and likeminded partners have advanced cooperative frameworks aimed at reinforcing maritime norms. Multilateral platforms such as the Indian Ocean Rim Association emphasise openness, inclusivity, and respect for international law. Beyond diplomatic forums, practical cooperation has intensified as states seek to translate abstract norms into enforceable mechanisms. Initiatives focused on maritime domain awareness, interoperability, and legal capacity-building demonstrate that the rules-based order depends on operational capability rather than mere normative agreement. 

The Indo-Pacific Partnership for Maritime Domain Awareness, launched by the Quadrilateral Security Dialogue, provides near real-time maritime surveillance and information-sharing to regional states, enabling them to detect illegal activities and enforce maritime law more effectively. In this context, the Quad functions not only as a cooperative platform but as a mechanism for aggregating strategic capacity, supporting interoperability, and strengthening maritime governance across the Indo-Pacific region. These developments indicate the rules-based order is increasingly being operationalised through coordinated capability building and selective enforcement, particularly in response to challenges such as illegal fishing and grey zone maritime activities.

Great-power competition and strategic balancing

The interplay between China, India, and the US represents the core axis of strategic competition in the Indian Ocean. For Washington, US, the region forms a vital component of its Indo-Pacific strategy, which envisions a free, open, and prosperous maritime domain anchored in international law.

India, while historically nonaligned, has expanded defence cooperation with the US and other Quad members. Joint exercises, technological collaboration, and enhanced surveillance systems reflect efforts to institutionalise mechanisms capable of deterring unilateral coercion while preserving strategic autonomy.

Smaller states and emerging challenges

Smaller IOR States including Sri Lanka, the Maldives, and the Seychelles remain critical actors in shaping regional dynamics: their policy decisions on defence cooperation, port access, and maritime regulation directly influence the durability of the regional order by affecting information sharing, multilateral security cooperation, and strategic alignments among larger powers. At the same time, these nations confront non-traditional security threats such as climate change, which endangers coastal infrastructure, and illegal, unreported, and unregulated fishing, which undermines economic sustainability and maritime governance.

The future of the rules-based Order in the Indian Ocean

The sustainability of a rules-based order in the Indian Ocean will depend on several key factors. First, major powers must demonstrate consistent commitment to international norms, ensuring that legal principles remain operational rather than rhetorical. Second, strengthening multilateral institutions can provide mechanisms for dialogue, confidence-building, and dispute management. Third, capacity-building assistance to smaller littoral states will be essential to ensure effective maritime governance across the region.

SL’s nat. security and the rules-based order

Sri Lanka’s geographic location in the centre of the Indian Ocean places it close to some of the world’s most important SLOCs. A large portion of global trade and energy shipments passes near Sri Lanka’s maritime boundaries. Therefore, the stability of the rules-based maritime order directly affects Sri Lanka’s economic security, maritime safety, maritime security and national interests.

For Sri Lanka, maintaining a stable and rules-based maritime environment is essential for protecting trade routes, preventing illegal activities such as drug trafficking and illegal fishing, and ensuring maritime security. To address these challenges, Sri Lanka continues to support international maritime law, particularly the UNCLOS, while strengthening maritime domain awareness and cooperation with regional partners.

Conclusion

The IOR stands at a strategic crossroads. As major powers expand their presence and pursue competing visions, the resilience of the rules-based maritime order will significantly shape regional security and global economic stability. Upholding this order requires more than declaratory support; it demands consistent adherence to international law, respect for sovereignty, and sustained multilateral cooperation. The choices made today will define the geopolitical trajectory of the Indian Ocean for decades to come.

The writer is a Military Research Officer at the Institute of National Security Studies under the Defence Ministry

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The views and opinions expressed in this column are those of the author, and do not necessarily reflect those of this publication