26 February 2026
CO26032 | ASEAN and the Indian Ocean: Bridging the Strategic Gap
SYNOPSIS
Donald Trump’s recent comments on Diego Garcia highlight evolving power dynamics in the Indian Ocean Region. ASEAN, despite its strategic interests in the region, has prioritised issues in the Pacific Ocean over more pressing challenges. Nevertheless, ASEAN must better balance its competing priorities to protect its core interests in the Indian Ocean.
COMMENTARY
Southeast Asia lies at the crossroads of the Indian and Pacific Oceans. ASEAN includes five Indian Ocean littoral states – Singapore, Malaysia, Indonesia, Thailand, and Myanmar. It is therefore keenly aware that the Indian Ocean Region (IOR), with its vital maritime sea lanes, underpins Southeast Asia’s export-driven economies, supplies essential energy resources, and sustains regional connectivity.
However, in terms of policy, apart from the introduction of the ASEAN Outlook on the Indo-Pacific (AOIP), ASEAN states have rarely regarded the two oceans as a unified strategic region. Instead, ASEAN’s institutional focus, perhaps understandably, remains mainly centred on the Pacific, given pressing issues such as the South China Sea and the wider impact of the US-China rivalry on Southeast Asia.
The recent controversy over Diego Garcia shows that the Indian Ocean should no longer be considered a secondary theatre, and that ASEAN must reassess its priorities more effectively to protect its core interests.
The Diego Garcia Controversy
On 20 January 2026, US President Donald Trump criticised the UK’s 2024 deal to transfer sovereignty of the Chagos Archipelago to Mauritius in exchange for the continued operation of the joint US-UK military base on its largest island, Diego Garcia. He labelled the deal, which had previously received American endorsement in 2025, as an act of “total weakness” and “great stupidity”.
Although he ultimately described the arrangement as the best deal available, he emphasised that the US retains the right to “militarily secure” the island to protect American interests in the Indian Ocean. Despite rhetorical inconsistencies, the broader message was clear: Washington remains committed to keeping Diego Garcia as a strategic stronghold in the IOR.
America in the Indian Ocean
This then raises the question – why is Diego Garcia so important? Diego Garcia, as the only permanent American military base in the Indian Ocean, anchors the US presence, with regular naval deployments safeguarding vital energy and trade routes across critical sea lanes connecting Europe and East, South, and West Asia.
Strategically, Diego Garcia enables the US to maintain maritime access and a favourable balance of power. Increasingly, this involves collaborating with regional partners – most notably India – to prevent any single actor from dominating the IOR.
This key American objective was reaffirmed during the Committee on Foreign Affairs Subcommittee hearing on South and Central Asia on 4 February, with the State Department’s Assistant Secretary, Paul Kapur, emphasising the importance of the Indian Ocean to America’s broader Indo-Pacific strategy.
The China-India Dynamic in the Indian Ocean
Although the United States has long been the dominant naval power in the IOR, the region’s security order is increasingly shaped by China-India competition. While border tensions eased after the 2024 disengagement agreement, maritime rivalry has grown stronger, characterised by competing institutional frameworks, infrastructure development, naval deployments, and partnerships.
China’s strategy has three main components. First, China has strengthened its political influence through its Belt and Road Initiative (BRI), which funds infrastructure projects along the “Maritime Silk Road” in the IOR, including ports, roads, and airports.
Secondly, China has deployed research vessels with intelligence-gathering capabilities, raising concerns in India, especially when docking in Sri Lanka and the Maldives.
Thirdly, China’s establishment of the China-Indian Ocean Regional Forum (CIORF) in 2022 enables it to take on institutional leadership and promote cooperation in areas such as the blue economy, whilst subtly challenging India’s Indian Ocean Conference (IOC).
These actions encroach on India’s dominance in the IOR, a region which India regards as its traditional “backyard”. India’s response has been gradual. It has strengthened multilateral institutions that exclude China, including the Indian Ocean Naval Symposium (IONS), Colombo Security Conclave (CSC), Information Fusion Centre-Indian Ocean Region (IFC-IOR), and the Quadrilateral Security Dialogue (QUAD).
Critical of China’s BRI, India has advanced alternative connectivity projects, such as the India–Middle East–Europe Economic Corridor (IMEC), the India–Myanmar–Thailand Trilateral Highway (IMTT), and the International North South Transport Corridor (INSTC). Moreover, through its MAHASAGAR initiative, India has launched the Africa–India Key Maritime Engagement and the Indian Ocean Ship Sagar deployment, thereby expanding maritime security cooperation with littoral states.
A Congested, Multipolar Indian Ocean Region
Regional players such as the UK, France (which has territories in the southwestern Indian Ocean), Australia (which has designated the IOR as part of its immediate region), Japan (which has been a key developmental partner), and the Gulf states have also bolstered their maritime roles.
The outcome is a progressively more congested strategic landscape. The Indian Ocean, previously characterised as relatively peaceful compared to the Pacific, now shows signs of multipolar rivalry among major powers.
Drivers of ASEAN’s Blindspot
Despite developments in the IOR, ASEAN’s engagement remains notably limited. Its institutional capacity is primarily occupied by more pressing concerns, such as the escalating situation in the South China Sea, and internal issues, including Myanmar’s political crisis, the Thailand-Cambodia conflict, and Timor-Leste’s integration. These matters already make it a challenge for ASEAN to maintain unity amid diverging national interests.
While the AOIP recognises the indivisibility of both oceans, ASEAN’s priorities mean that Indian Ocean issues seldom appear in ASEAN communiques or summit declarations. Moreover, the current ASEAN-led institutional frameworks mainly focus on East Asia’s security challenges and lack specific mechanisms for engagement in the Indian Ocean.
This is concerning because ASEAN’s economic lifelines pass through the Indian Ocean. It also faces other issues, such as piracy, illegal fishing, and climate-related challenges originating in the western theatre. Essentially, this means ASEAN could do without the escalating competitive tensions within the IOR.
What Can ASEAN Do?
Given the vast size of the Indian Ocean, it would be unrealistic for ASEAN to take a leading role in developing a favourable regional security architecture. Instead, it could begin by attempting the following:
First, ASEAN could reinforce its institutional links with regional and subregional groups, such as the Indian Ocean Rim Association (IORA) and the Bay of Bengal Initiative for Multisectoral Technical and Economic Cooperation (BIMSTEC). For example, ASEAN could seek to renew the 2023 ASEAN–IORA Memorandum of Understanding (MOU), which expired in 2025, to expand the scope of practical cooperation.
It could also seek membership as a dialogue partner in the IORA, thereby enabling ASEAN to represent its interests as a regional bloc, for example, by emphasising adherence to international law and norms at IORA forums. It could also share ASEAN’s experience in navigating such challenges in the Pacific Ocean to help IORA states derive applicable lessons.
Secondly, in the medium term, ASEAN might include the Indian Ocean into ASEAN-led regional mechanisms such as the ASEAN Maritime Forum, ASEAN Regional Forum, or the East Asia Summit. Working groups could be established to address relevant issues, including energy security, the security of critical marine infrastructure, and climate change-related challenges.
Regular agenda items would place the IOR firmly within ASEAN’s Indo-Pacific vision. Given the unrealistic expectation of equal involvement from all ASEAN states, the ASEAN littoral states should appoint lead countries for specific issue areas.
Conclusion
The Diego Garcia controversy illustrates the shifting power dynamics in the Indian Ocean Region. ASEAN could adopt a more proactive role in establishing networks and fostering more regular engagement among major powers and littoral states to lessen competitive tensions in the Indian Ocean.
About the Author
Arvind Raj is an Associate Research Fellow at the Centre for Multilateralism Studies, S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University (NTU).
SYNOPSIS
Donald Trump’s recent comments on Diego Garcia highlight evolving power dynamics in the Indian Ocean Region. ASEAN, despite its strategic interests in the region, has prioritised issues in the Pacific Ocean over more pressing challenges. Nevertheless, ASEAN must better balance its competing priorities to protect its core interests in the Indian Ocean.
COMMENTARY
Southeast Asia lies at the crossroads of the Indian and Pacific Oceans. ASEAN includes five Indian Ocean littoral states – Singapore, Malaysia, Indonesia, Thailand, and Myanmar. It is therefore keenly aware that the Indian Ocean Region (IOR), with its vital maritime sea lanes, underpins Southeast Asia’s export-driven economies, supplies essential energy resources, and sustains regional connectivity.
However, in terms of policy, apart from the introduction of the ASEAN Outlook on the Indo-Pacific (AOIP), ASEAN states have rarely regarded the two oceans as a unified strategic region. Instead, ASEAN’s institutional focus, perhaps understandably, remains mainly centred on the Pacific, given pressing issues such as the South China Sea and the wider impact of the US-China rivalry on Southeast Asia.
The recent controversy over Diego Garcia shows that the Indian Ocean should no longer be considered a secondary theatre, and that ASEAN must reassess its priorities more effectively to protect its core interests.
The Diego Garcia Controversy
On 20 January 2026, US President Donald Trump criticised the UK’s 2024 deal to transfer sovereignty of the Chagos Archipelago to Mauritius in exchange for the continued operation of the joint US-UK military base on its largest island, Diego Garcia. He labelled the deal, which had previously received American endorsement in 2025, as an act of “total weakness” and “great stupidity”.
Although he ultimately described the arrangement as the best deal available, he emphasised that the US retains the right to “militarily secure” the island to protect American interests in the Indian Ocean. Despite rhetorical inconsistencies, the broader message was clear: Washington remains committed to keeping Diego Garcia as a strategic stronghold in the IOR.
America in the Indian Ocean
This then raises the question – why is Diego Garcia so important? Diego Garcia, as the only permanent American military base in the Indian Ocean, anchors the US presence, with regular naval deployments safeguarding vital energy and trade routes across critical sea lanes connecting Europe and East, South, and West Asia.
Strategically, Diego Garcia enables the US to maintain maritime access and a favourable balance of power. Increasingly, this involves collaborating with regional partners – most notably India – to prevent any single actor from dominating the IOR.
This key American objective was reaffirmed during the Committee on Foreign Affairs Subcommittee hearing on South and Central Asia on 4 February, with the State Department’s Assistant Secretary, Paul Kapur, emphasising the importance of the Indian Ocean to America’s broader Indo-Pacific strategy.
The China-India Dynamic in the Indian Ocean
Although the United States has long been the dominant naval power in the IOR, the region’s security order is increasingly shaped by China-India competition. While border tensions eased after the 2024 disengagement agreement, maritime rivalry has grown stronger, characterised by competing institutional frameworks, infrastructure development, naval deployments, and partnerships.
China’s strategy has three main components. First, China has strengthened its political influence through its Belt and Road Initiative (BRI), which funds infrastructure projects along the “Maritime Silk Road” in the IOR, including ports, roads, and airports.
Secondly, China has deployed research vessels with intelligence-gathering capabilities, raising concerns in India, especially when docking in Sri Lanka and the Maldives.
Thirdly, China’s establishment of the China-Indian Ocean Regional Forum (CIORF) in 2022 enables it to take on institutional leadership and promote cooperation in areas such as the blue economy, whilst subtly challenging India’s Indian Ocean Conference (IOC).
These actions encroach on India’s dominance in the IOR, a region which India regards as its traditional “backyard”. India’s response has been gradual. It has strengthened multilateral institutions that exclude China, including the Indian Ocean Naval Symposium (IONS), Colombo Security Conclave (CSC), Information Fusion Centre-Indian Ocean Region (IFC-IOR), and the Quadrilateral Security Dialogue (QUAD).
Critical of China’s BRI, India has advanced alternative connectivity projects, such as the India–Middle East–Europe Economic Corridor (IMEC), the India–Myanmar–Thailand Trilateral Highway (IMTT), and the International North South Transport Corridor (INSTC). Moreover, through its MAHASAGAR initiative, India has launched the Africa–India Key Maritime Engagement and the Indian Ocean Ship Sagar deployment, thereby expanding maritime security cooperation with littoral states.
A Congested, Multipolar Indian Ocean Region
Regional players such as the UK, France (which has territories in the southwestern Indian Ocean), Australia (which has designated the IOR as part of its immediate region), Japan (which has been a key developmental partner), and the Gulf states have also bolstered their maritime roles.
The outcome is a progressively more congested strategic landscape. The Indian Ocean, previously characterised as relatively peaceful compared to the Pacific, now shows signs of multipolar rivalry among major powers.
Drivers of ASEAN’s Blindspot
Despite developments in the IOR, ASEAN’s engagement remains notably limited. Its institutional capacity is primarily occupied by more pressing concerns, such as the escalating situation in the South China Sea, and internal issues, including Myanmar’s political crisis, the Thailand-Cambodia conflict, and Timor-Leste’s integration. These matters already make it a challenge for ASEAN to maintain unity amid diverging national interests.
While the AOIP recognises the indivisibility of both oceans, ASEAN’s priorities mean that Indian Ocean issues seldom appear in ASEAN communiques or summit declarations. Moreover, the current ASEAN-led institutional frameworks mainly focus on East Asia’s security challenges and lack specific mechanisms for engagement in the Indian Ocean.
This is concerning because ASEAN’s economic lifelines pass through the Indian Ocean. It also faces other issues, such as piracy, illegal fishing, and climate-related challenges originating in the western theatre. Essentially, this means ASEAN could do without the escalating competitive tensions within the IOR.
What Can ASEAN Do?
Given the vast size of the Indian Ocean, it would be unrealistic for ASEAN to take a leading role in developing a favourable regional security architecture. Instead, it could begin by attempting the following:
First, ASEAN could reinforce its institutional links with regional and subregional groups, such as the Indian Ocean Rim Association (IORA) and the Bay of Bengal Initiative for Multisectoral Technical and Economic Cooperation (BIMSTEC). For example, ASEAN could seek to renew the 2023 ASEAN–IORA Memorandum of Understanding (MOU), which expired in 2025, to expand the scope of practical cooperation.
It could also seek membership as a dialogue partner in the IORA, thereby enabling ASEAN to represent its interests as a regional bloc, for example, by emphasising adherence to international law and norms at IORA forums. It could also share ASEAN’s experience in navigating such challenges in the Pacific Ocean to help IORA states derive applicable lessons.
Secondly, in the medium term, ASEAN might include the Indian Ocean into ASEAN-led regional mechanisms such as the ASEAN Maritime Forum, ASEAN Regional Forum, or the East Asia Summit. Working groups could be established to address relevant issues, including energy security, the security of critical marine infrastructure, and climate change-related challenges.
Regular agenda items would place the IOR firmly within ASEAN’s Indo-Pacific vision. Given the unrealistic expectation of equal involvement from all ASEAN states, the ASEAN littoral states should appoint lead countries for specific issue areas.
Conclusion
The Diego Garcia controversy illustrates the shifting power dynamics in the Indian Ocean Region. ASEAN could adopt a more proactive role in establishing networks and fostering more regular engagement among major powers and littoral states to lessen competitive tensions in the Indian Ocean.
About the Author
Arvind Raj is an Associate Research Fellow at the Centre for Multilateralism Studies, S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University (NTU).
