The Malacca Strait Dilemma and Lessons from the Strait of Hormuz

The Malacca Strait, separating the Malay Peninsula and Sumatra Island, serves as a pivotal maritime route in the Indo-Pacific. The strait is highly strategic as a shipping lane for merchant and naval vessels. Nearly 24 per cent of global cross-trade is transported through the Malacca Strait, meaning disruptions could lead to economic or security crises.

Currently, the Malacca Strait is under global scrutiny following Iran’s and the US’s blockade of the Strait of Hormuz. Many parties fear a similar incident in the Malacca Strait, whether due to natural disasters, ship groundings, or war.

If that occurs, an economic crisis would be unavoidable. This is possible because the Malacca Strait is vital for many countries. For instance, China transports nearly 75 per cent of its crude oil imports from the Middle East, Africa, and Asia through the Malacca Strait. Japan and South Korea also route 90 per cent of their oil through it. The strait is so crucial that former Chinese President Hu Jintao referred to it as the ‘Malacca Dilemma’.

In 2025, more than 102,000 vessels of various types passed through the narrow 900-kilometre waters. The flow of goods carried through the Malacca Strait accounts for one-third of world trade. On average, 23 million barrels of oil are transported daily via this route, making the Malacca Strait the world’s busiest oil chokepoint, surpassing the Strait of Hormuz.

Yet the Malacca Strait is very narrow: its narrowest point, the Phillips Channel in the Singapore Strait, is only 2.7 kilometres wide. Moreover, the Malacca Strait is shallow. In some sections, the water depth is only 25-27 metres. Giant VLCC (Very Large Crude Carrier) and ULCV (Ultra Large Container Vessel) ships, unable to pass due to draft limitations or large cargo capacity, must detour via the Sunda Strait or Lombok Strait. However, this option adds thousands of nautical miles and operational costs amounting to tens of thousands of dollars. From this situation, it is evident how high the price would be if the Malacca Strait experiences disruptions.

Navigation security in the Malacca Strait is the responsibility of Indonesia, Malaysia, and Singapore. The International Maritime Organisation (IMO) has established a Traffic Separation Scheme (TSS) in the Malacca Strait to regulate shipping traffic for vessel safety in the narrow lanes.

Lessons from the Strait of Hormuz

Like the Malacca Strait, the Strait of Hormuz, separating Iranian territory from the Arabian Peninsula in the regions of Oman and the United Arab Emirates, is also a strategic chokepoint for the world’s economy. Iran closed the strait during the war against the US and Israel, disrupting the global economy. The blockade of the Strait of Hormuz disrupted global oil supplies by up to 20 per cent, causing a surge in world oil prices.

Asymmetric naval warfare and Iran’s closure of the Strait of Hormuz have dramatically altered maritime geopolitical calculations. It turns out that a narrow but strategic strait can deliver a shock effect in an unbalanced war in terms of weaponry. Although Iran suffered significant civilian casualties, the strategy employed by Iran was able to halt the US-Israel attacks.

Currently, the war status is a two-week ceasefire since 18 April 2026, which has been extended by the US. Although the first round of talks mediated by Pakistan failed to reach an agreement, hopes for returning to the negotiating table remain open, just as open as the possibility of the US and Israel resuming assaults on Iran.

Reflecting on that war, what lessons can we draw from the asymmetric Iran-US-Israel conflict, particularly regarding the existence of the Malacca Strait, Sunda Strait, and Lombok Strait as global shipping chokepoints.

A chokepoint holds great significance for sailors navigating the oceans. All sailors certainly choose the shortest shipping route to their destination port for efficiency in time and cost. That is why chokepoints like straits and canals are always busy with vessel traffic, as seen in the Malacca Strait, Strait of Hormuz, Suez Canal, Panama Canal, Strait of Gibraltar, Bab el-Mandeb Strait, Bosphorus Strait, Lombok Strait, and Sunda Strait.

To maintain chokepoint security, Indonesia proposed three Indonesian Archipelagic Sea Lanes (ALKI) based on the UN Convention on the Law of the Sea (UNCLOS) to the International Maritime Organisation (IMO), implemented through an IMO Resolution. These three ALKIs include ALKI I in the Malacca Strait and Singapore Strait, a north-south corridor from the Indian Ocean to the South China Sea. This is the busiest route connecting Europe, the Middle East, and South Asia with China, Japan, and South Korea.

Then ALKI II, the Lombok Strait and Makassar Strait, serves as an alternative passage for large-laden ships that cannot pass through the Malacca Strait, and ALKI III in the Sape Strait and Ombai (Wetar) Strait, connecting the Pacific Ocean and Indian Ocean via the eastern route. This route is relevant for military operations and commercial shipping to avoid congestion in the Malacca Strait.

The existence of ALKI and the chokepoints of the Malacca Strait, Sunda Strait, and Lombok Strait must be safeguarded and their security anticipated so that no major power imposes its will there through blockades. For that, adjustments to defence doctrine are needed in case of blockades.

Marsetio

Professor at the National Defence University; Former Chief of Naval Staff