The Strait of Malacca, a 900-kilometre freight corridor linking the Indian Ocean to the South China Sea, could become the next global flashpoint as major powers bolster their military presence in the region. While recent international attention has centred on the Strait of Hormuz, where Iran has effectively halted shipping since late February, a quieter but equally significant development has been unfolding in Southeast Asia.
US-Indonesia Defence Partnership
On April 14, the United States and Indonesia announced a major defence cooperation partnership, strengthening their military ties. Reports indicate that the US is also seeking broader access to Indonesian airspace, with Indonesian President Prabowo Subianto reportedly approving the proposal. These moves are significant because Indonesia’s vast archipelago straddles some of the world’s most critical sea routes, including the Strait of Malacca.
Strategic Importance of the Strait
The Strait of Malacca is the shortest sea route connecting the Indian Ocean to the South China Sea and the Pacific Ocean, making it the default corridor for trade between East Asia and the West. It stretches roughly 900 kilometres from the Malay Peninsula to the Indonesian island of Sumatra. At its narrowest point, the Phillips Channel near Singapore, it is barely 2.8 kilometres wide.
Almost 24% of global seaborne trade by volume flows through the strait. It carries 45% of the world’s seaborne oil, over 25% of all cars traded internationally, and 23% of dry bulk cargo, including key agricultural commodities like grains and soybeans. A large portion of European imports of electronics, consumer products such as footwear and toys, machinery, and industrial goods also pass through the strait in sea containers.
Critical Port Infrastructure
The strait is home to some of the world’s most critical port infrastructure. Singapore, located at the strait’s southern entrance, is the second-busiest container port and the busiest container transshipment hub on the planet. It handles over 40 million containers annually and is the world’s largest ship refuelling hub. Port Klang in Malaysia ranks among the world’s top ten container ports, handling 14 million containers each year.
Why Malacca Is Irreplaceable
The most commonly cited detours around the Strait of Malacca—the Sunda and Lombok Straits—both lie within Indonesian territory and are not straightforward substitutes. Rerouting through either adds roughly 1,000 to 1,500 nautical miles to the journey, equating to three to five extra days at sea, along with higher fuel costs and the loss of Singapore’s refuelling infrastructure. Beyond Indonesia, the Torres Strait near Papua New Guinea is too shallow for large commercial vessels with a draft of over 12 metres. Ships avoiding all these routes would face a detour around the entire Australian continent, adding another ten to 15 days of transit time. These geographical constraints make the Strait of Malacca extremely difficult to bypass.
China's Malacca Dilemma
China understands the risk of relying on the Strait of Malacca perhaps better than anyone. In 2003, then-President Hu Jintao coined the phrase “Malacca dilemma” to describe a strategic exposure that persists today. Between 75% and 80% of China’s imported oil still passes through the strait. Beijing has invested heavily in alternatives, but none come close to matching the scale of what transits Malacca.
Pipelines running from Kyaukpyu on the Bay of Bengal in Myanmar into Yunnan province in China bypass Malacca entirely, but their capacity is only around 440,000 barrels per day—a small fraction of China’s roughly 11 million barrels of daily oil imports. The China-Pakistan Economic Corridor plans to link Gwadar Port on the Arabian Sea to Xinjiang in north-west China through road, rail, and energy infrastructure, but it remains only partially developed, hindered by difficult terrain and security challenges in parts of Pakistan. China has also diversified through Central Asian oil and gas pipelines, which provide about 10% of its total imported oil.
Rail freight corridors connecting China to Europe avoid maritime chokepoints entirely and are faster than shipping, but they are far more expensive and very limited in capacity. Arctic shipping routes along Russia’s northern coast offer a longer-term hedge, cutting the distance between Asia and Europe, but remain seasonal and marginal in global trade terms.
Growing Military Presence
Both the US and China have been steadily expanding their military presence around the strait and its approaches. The US has largely done so through base access and naval deployments, while China has pursued a port network and naval buildup. The Andaman and Nicobar Islands, located near the strait’s western approaches, also provide India with a strategic presence in the region. Southeast Asia is becoming more explicitly tied into great-power competition, with the new US-Indonesia defence partnership adding the latest layer. Should this competition intensify—whether through a crisis in Taiwan, a spillover from Hormuz, or a shift in alliances—the Strait of Malacca would be at the centre of it.
For now, there is no clear indication that the growing military presence around the strait will have any immediate impact on commercial shipping. However, if a conflict does arise in the future, it will be trade-dependent economies like China that will suffer most.
