Indonesia is at the centre of much of the world’s maritime trade, and its foreign and defence policies, especially regarding control over its maritime waterways, can have a substantial impact on the world stage. Yet, while this is undoubtedly a geographical blessing, it can also be a source of pressure and tension with the great powers.
Iran’s total blockade of the Strait of Hormuz has underscored the importance of maritime chokepoints, and Indonesia sits astride some of the world’s most critical maritime ones: the Malacca Strait (shared with Malaysia) and its own archipelagic waters, within which the Sunda, Lombok, and Makassar Straits are squarely located. Ships destined for the Industrial powerhouses of East and Southeast Asia from the Indian Ocean would have to traverse either of those two straits for an expeditious journey (and vice versa). While governed by international transit rights, these waterways remain geographically and strategically shaped by Indonesia’s archipelagic position
The Indonesian government estimates that 40 per cent of global maritime trade passed through its archipelagic waters in 2019, underscoring the density—if not absolute control—of traffic through these routes. Additionally, a substantial majority of China’s energy needs passed through the Strait of Malacca in 2024, not to mention ships carrying energy to Japan, South Korea, Vietnam, Taiwan, and other East and Southeast Asian countries. At its narrowest point, the Strait of Malacca is only 2.4 kilometres wide, making it a tight bottleneck that many ships must pass through.
If Indonesia’s waterways were untraversable, the consequences would be substantial. Ships would face delays due to narrower routes or detours around Papua New Guinea, increasing transit times and costs and straining regional supply chains.
The Blessings of Geography
Consequently, Indonesia is at the centre of much of the world’s maritime trade, and its foreign and defence policies, especially regarding control over its maritime waterways, can have a substantial impact on the world stage. Yet, while this is undoubtedly a geographical blessing, it can also be a source of pressure and tension with the great powers.
Such a central position means that major powers must secure Indonesia’s goodwill to maintain smooth maritime trade flows and ensure a stable global supply chain, a vital component in maintaining economic stability in their own countries, directly or indirectly. This gives Jakarta considerable leverage in navigating between the major powers and pursuing its interests, as highlighted by Evan Laksmana and Chatib Basri.
This leverage, however, is not absolute. Major powers retain operational and legal means to mitigate dependence on Indonesia’s waterways, and alternative routes—though costlier—do exist
Even so, Indonesia has greater room for manoeuvre than is often assumed. In the North Natuna Sea, for instance, Jakarta need not acquiesce to China’s maritime claims. Past enforcement actions, including the sinking of illegal fishing vessels and opening fire on a Chinese fishing boat, under President Joko Widodo’s first administration, did not derail broader economic ties with Beijing. While such incidents fall short of high-intensity conflict, they suggest that limited assertiveness of Indonesia’s core interests does not automatically trigger severe retaliation.
Yet this same leverage creates strategic exposure to external pressure. The more central Indonesia is to global trade, the higher the stakes of its decisions. Its policies could shape the dynamics of regional conflict, making it a target of pressure from competing powers.
With Great Leverage Comes Great Responsibility
Given how much of China’s trade passes through the Malacca Strait or Indonesia’s waters, Jakarta may receive pressure from Washington, D.C., to allow the US military to operate more freely inside Indonesia’s waters. US military ships and planes can already pass through Indonesia’s designated archipelagic sea lanes freely if the passage is expeditious, does not affect Indonesia’s security, and does not deviate from Indonesia’s prescribed Archipelagic Sea Lanes (ASL). Yet, the US military may want a higher latitude of freedom to operate inside Indonesia’s waters that goes beyond the allowed innocent passages under the UN Convention on the Law of the Sea, as evidenced by the US proposal for a blanket overflight access over Indonesian territory beyond Indonesia’s prescribed ASL that would allow US military planes to save hours of flight time without a cumbersome authorisation process.
Such a scenario is especially acute in the hypothetical case of a Chinese blockade or invasion of Taiwan, and the United States imposes a counter-blockade operation to cut off China’s petroleum supplies and trade routes through the Strait of Malacca and Indonesia’s archipelagic waters. Indonesia may face US pressure to allow the US Navy to operate in its waters and Chinese pressure to prevent it. Any option that Indonesia takes would inevitably favour one side of the conflict and may invite adverse reaction from the other side. Indonesia’s cherished policy of neutrality in such a scenario would be untenable. Other regional actors, including Japan and Australia, would likely also have a stake in such a scenario, further complicating Indonesia’s strategic calculus
Indonesia must therefore prepare for scenarios in which its geographic position becomes both a source of influence and a constraint. This includes strengthening maritime domain awareness, clarifying its stance on access during contingencies, and developing credible deterrence within its archipelagic waters. Most importantly, Indonesia must build the diplomatic, military, and economic resilience needed to withstand external pressure and maintain strategic autonomy. Geography may be immutable, but how Indonesia chooses to wield it will determine whether it shapes events—or is shaped by them.
Trystanto Sanjayais a Visiting Fellow at the Norwegian Institute of International Affairs in Oslo. All views are personal.
This article is published under a Creative Commons License and may be republished with attribution.
