The US-Israel war on Iran underscores how conflicts in West Asia can swiftly disrupt the maritime arteries sustaining the Indo-Pacific
The ongoing US-Israel war on Iran has been geographically distant from the Indo-Pacific, yet its consequences have been felt most acutely across Asia’s maritime economies. The majority of energy transported through the Persian Gulf is consumed in the region, with over 80 percent of the oil and liquefied natural gas shipped through the Strait of Hormuz bound for Asian markets, with China, South Korea, Japan, and India among the largest importers. The widening maritime dimension of the war, including the sinking of the Iranian frigate IRIS Dena in the Indian Ocean, has forced governments from Tokyo to Jakarta to confront the reality that conflicts in West Asia can rapidly spill into the Indo-Pacific maritime space.
The sinking of the Iranian naval vessel IRIS Dena marked a particularly striking moment in that spillover. A US submarine torpedoed the frigate in early March 2026 while it was operating in the Indian Ocean near Sri Lanka, killing dozens of sailors and dramatically expanding the geographic scope of the war beyond the Persian Gulf. Washington justified the strike by arguing that the vessel was a legitimate military target; Tehran insisted the ship was not engaged in combat operations. The episode occurred thousands of kilometres from the main theatre of war, underscoring that naval operations linked to the conflict now extend deep into the wider Indo-Pacific maritime space.
The widening maritime dimension of the war, including the sinking of the Iranian frigate IRIS Dena in the Indian Ocean, has forced governments from Tokyo to Jakarta to confront the reality that conflicts in West Asia can rapidly spill into the Indo-Pacific maritime space.
From a maritime perspective, the attack was significant not merely because a naval vessel was sunk, but because of where it occurred. The strike took place off Sri Lanka, close to major sea lanes connecting West Asia with East Asia. The operation indicated a strategic extension of the battlespace into the Indian Ocean, demonstrating that Iranian naval assets could be targeted well beyond the Persian Gulf. The distinction between a regional conflict in West Asia and a broader maritime conflict affecting the sea lines of communication that support Indo-Pacific trade was effectively blurred. The crisis has also reinforced the significance of maritime security cooperation, with G7 nations mulling the possibility of escort missions or mine-countermeasure deployments in the Persian Gulf.
Japan’s reaction illustrates the vulnerability felt across Northeast Asia. Tokyo imports the overwhelming majority of its oil from West Asia, with roughly 70 percent of its crude supplies passing through the Strait of Hormuz. Any disruption to shipping in the region, therefore, immediately becomes a national security issue. Japanese policymakers have responded cautiously: while emphasising the need to maintain freedom of navigation and protect energy flows, they have avoided explicitly endorsing US military actions against Iran. At the same time, Washington has pressured Tokyo to contribute naval assets to protect shipping routes, placing Japan in a difficult position between alliance commitments and constitutional constraints on military operations abroad.
South Korea faces a similar dilemma. Like Tokyo, Seoul relies heavily on energy imports from the Gulf and has historically deployed limited naval forces to the region to protect shipping. Korean policymakers have therefore focused on safeguarding sea lanes rather than participating in combat operations. The crisis has revived discussion in Seoul, amid Washington’s pressure, about the role of the Cheonghae naval unit, originally deployed for anti-piracy operations, in protecting merchant vessels transiting the region. Yet the expansion of hostilities into the wider Indian Ocean suggests that protecting shipping may no longer be a narrowly defined constabulary task. Rather, it might necessitate navigating the many legal and practical difficulties of a high-stakes naval confrontation between powerful nations.
At present, several Indo-Pacific nations find themselves in a difficult position, debating whether to contribute naval assets to international initiatives aimed at keeping the Strait of Hormuz open.
Australia’s perspective is somewhat different, but no less significant. As a major energy exporter rather than importer, Canberra’s concern lies less in supply disruption than in the stability of maritime trade networks and alliance commitments. Australia's significance as a substitute supplier of LNG to Northeast Asia has been highlighted by the crisis. Japanese officials have already sought assurances from Canberra that LNG exports from Australia help offset supply delays caused by the conflict. At the same time, Australia’s longstanding participation in US-led maritime security initiatives in the Gulf suggests that Canberra could again be drawn into coalition efforts to secure shipping routes.
In Southeast Asian states, the conflict is being viewed primarily through the lens of neutrality and economic vulnerability. Most ASEAN countries have refrained from taking sides, calling for restraint while keeping a close eye on the impact on the energy and shipping industries. However, the IRIS Dena incident showed how swiftly the conflict could spill into the immediate vicinity of Southeast Asia. The strike occurred close enough to Sri Lanka that the country suddenly found itself managing survivors and responding to diplomatic pressure from both Tehran and Washington. The episode underscores how smaller littoral states along the Indian Ocean’s sea lanes can be drawn unexpectedly into the geopolitical consequences of distant conflicts. For Southeast Asian countries that depend heavily on maritime trade, particularly for energy imports from West Asia, chokepoint vulnerability remains a major concern. Consequently, governments across the region are closely monitoring developments, from Singapore’s global shipping hub to Indonesia’s energy-importing industries. Disruption to Gulf shipping not only drives up energy prices but also alters shipping routes, insurance premiums, and the operational environment for merchant fleets traversing the Indo-Pacific.
China, too, has much to lose if the conflict continues. In recent years, Iran has become an important source of relatively cheap crude for China, which now relies heavily on energy supplies from West Asia. More than half of China’s seaborne crude imports originate in the region, with a significant share coming from Iran. At the same time, Chinese firms have expanded across West Asia in the renewable energy and technology sectors. As the largest buyer of Iranian oil, China is particularly exposed to rising energy prices and supply disruptions.
The maritime system that sustains Asian prosperity, from the oil terminals of the Gulf to the ports of Northeast Asia, cannot be neatly divided into separate regions.
The maritime implications extend beyond energy flows. The conflict has rekindled concerns about the safety of international maritime routes and the role of naval power in safeguarding them. At present, several Indo-Pacific nations find themselves in a difficult position, debating whether to contribute naval assets to international initiatives aimed at keeping the Strait of Hormuz open.
In strategic terms, the attack on IRIS Dena carries three broader implications for maritime security in the Indo-Pacific. First, it demonstrates the geographic elasticity of modern naval conflict: strikes can occur far beyond the immediate theatre of war, potentially drawing in states that are not direct participants. Second, it highlights the vulnerability of critical sea lanes connecting the Indo-Pacific to West Asia. Finally, it reinforces the growing interdependence between regional security theatres.
For Indo-Pacific policymakers, the lesson is stark. The maritime system that sustains Asian prosperity, from the oil terminals of the Gulf to the ports of Northeast Asia, cannot be neatly divided into separate regions. When conflict erupts in one part of that system, its shockwaves travel rapidly along the sea lanes that connect these regions. The ongoing conflict in West Asia is therefore more than a distant war. It's a reminder that the maritime order of the Indo-Pacific remains deeply entangled with events far beyond its immediate shores.
Pratnashree Basu is an Associate Fellow at the Observer Research Foundation.
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Pratnashree Basu is an Associate Fellow with the Strategic Studies Programme. She covers the Indo-Pacific region, with a focus on Japan’s role in the region. ...
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