Maritime Chokepoints Under Pressure Threaten 10% of Global GDP

A wave of disruptions, from Iran's effective closure of the Strait of Hormuz to China's escalating threats over the Taiwan Strait, is stressing the arteries of global commerce. These pressures are adding 10 to 14 days to shipping routes and have sent insurance premiums soaring, creating a 21st-century version of historic shipping tolls that impacts supply chains for everything from oil to semiconductors.

"While the U.S. might not fuel its cars with gas from the Middle East, its supply-chain partners in Asia and Europe certainly do," said Christopher Tang, a distinguished research professor at the UCLA Anderson School of Management. "When key waterways for transporting that energy seize up and our partners face an energy crisis, their ability to produce and ship goods to American shores is compromised. Prices go up for all."

The fallout is already visible in shipping data. Vessels are rerouting around Africa’s Cape of Good Hope to avoid Houthi attacks in the Bab el-Mandeb Strait, a detour that adds up to 14 days and significant operational costs. The Strait of Malacca, which handles roughly 25 percent of global trade, is now accommodating 60 percent more daily traffic, with piracy incidents hitting a 19-year high in 2025. Meanwhile, Iran's establishment of a de facto toll system in the Strait of Hormuz, through which 21 percent of global oil passes, has sent energy prices higher.

The most severe risk lies in the Taiwan Strait, a critical thruway for nearly 40 percent of the world’s semiconductors. A conflict there could erase up to $10.6 trillion, or nearly 10 percent of global GDP, according to one estimate from Bloomberg Economics. With Taiwan's major ports facing the strait and no geographical bypass, global tech and defense industries would face an immediate and catastrophic parts shortage.

A World of Waterway Weaponization

The current crises demonstrate that closing or controlling a strait has become a potent weapon for state and non-state actors. In late February, Iran’s Islamic Revolutionary Guard Corps used a combination of drones, anti-ship missiles, and mines to choke off the 21-nautical-mile-wide Strait of Hormuz. This tactic echoes the 1984 “tanker war” but with more effective and cheaper technology, allowing weaker states to impose significant costs on stronger adversaries.

This weaponization extends beyond outright military action. In the Bab el-Mandeb Strait, continued attacks by Yemeni Houthis have led ship insurers to classify the area as high-risk, hiking premiums that act as a tax on global trade. This financial pressure has proven as effective as a physical blockade in forcing a massive rerouting of commercial vessels.

The Semiconductor Jugular

Nowhere are the consequences of a potential blockade greater than the Taiwan Strait. Unlike the Strait of Malacca, which China is attempting to bypass with overland pipelines, Taiwan has no such alternative. Its economy is a lynchpin of global technology; it is the world’s dominant producer of advanced semiconductors.

A blockade would halt the export of these critical chips, paralyzing automotive and technology manufacturing worldwide. Bloomberg Economics has estimated the cost of a conflict at $10.6 trillion, while other analyses suggest a GDP loss of at least 5.3 percent. The 70-nautical-mile-wide strait, through which 20 percent of global maritime trade passes, is a distinct and acute vulnerability in the global economic system. The last time tensions flared significantly in the region, global equity markets saw a sharp increase in volatility, with the VIX index jumping several points.

Secondary Routes Under Strain

The pressure on primary chokepoints is creating new vulnerabilities in secondary waterways. With the Strait of Malacca now handling 440 ships a day, a 60 percent increase, traffic is beginning to divert through the Indonesian archipelago, including the Sunda and Lombok Straits.

This shift has not gone unnoticed by global powers. In early April, an unmanned underwater vehicle of suspected Chinese origin was discovered in the Lombok Strait, suggesting increased strategic focus on these alternate routes. Transit in these archipelagic waters is governed by specific sea-lane passage rules under the UN Convention on the Law of the Sea (UNCLOS), concentrating traffic into predictable corridors that are easier to monitor and potentially target.

This article is for informational purposes only and does not constitute investment advice.