When Chokepoints Break

The network we never see

Every day, around 60,000 merchant vessels are in transit across the world's oceans. 80% of everything we consume travels by sea.

This is the circulatory system of the global economy. And like any network, it has structure, and vulnerabilities.

Five narrow passages

All those routes funnel through a handful of straits. In network science, these nodes have high betweenness centrality: they matter not because of their size, but because of how many paths depend on them.

February 28, 2026

The US and Israel launched 900 strikes against Iran. Within hours, the IRGC sealed the Strait of Hormuz. 21 attacks on merchant ships. Sea mines laid across the shipping lanes.

For the first time in history, the world's most critical energy chokepoint went dark.

Daily vessel transits

A 95% collapse overnight. 13 million barrels of oil per day stopped flowing. Only 4-5 million can be rerouted through pipelines. The rest is stranded.

Who gets cut off

Japan imports 85% of its oil through Hormuz. South Korea 75%. Taiwan 80%.^[1] When the strait closed, their energy supply lines vanished.

Oil surged past $120 per barrel.^[2] Supertanker insurance hit all-time highs. Lufthansa cut 20,000 flights and KLM suspended Gulf overflights as jet fuel prices doubled.^[3]

Europe: a second front

With Bab el-Mandeb closed, Europe lost its shortest lane to Asia. Qatari LNG — critical for German and Italian industry — rerouted around Cape of Good Hope, adding 10–14 days and €2–4 per MWh to European gas prices.

German automakers faced parts shortages as semiconductor shipments from Malaysia piled up at Rotterdam. French and Spanish food processors scrambled as Egyptian fertilizers stalled in the Red Sea. The EU's just-in-time supply chains had no buffer for two simultaneous chokepoints.

Americas: drought and decoupling

The 2025–26 drought had already cut Panama Canal capacity to a third of normal. US Gulf Coast LNG and grain exports to Asia slowed to a trickle. Refiners who used Suez as their backup found that route compromised too.

Latin American exporters lost connectivity in both directions. Chilean copper, Brazilian iron ore, Argentine soy — all hitting bottlenecks. A region that assumed two ocean routes would balance saw both strained at once.

The double closure

The same day, Houthis in Yemen resumed Red Sea attacks. Bab el-Mandeb went down too. The Suez route became unreachable.

The only remaining path from the Gulf to Europe: around Africa's Cape of Good Hope. 3,500 extra nautical miles. 14 extra days at sea.

Beyond oil

Oil is the headline. But one-third of global fertilizer trade passes through Hormuz. One-third of methanol. Aluminum, helium, graphite.

Gulf states import 80% of their food by sea. By mid-March, 70% of food imports were disrupted. A grocery emergency across the GCC.

What the network reveals

The global shipping network was optimized for efficiency, not resilience. Remove one node with high betweenness centrality and the system fragments.

Toggle chokepoints to see how the network reorganizes:

Modeling before it breaks

The shipping industry spent decades optimizing for cost. Network modeling offers something different: the ability to run disruption scenarios before the crisis hits.

Organizations that map their supply networks can identify single points of failure — the nodes where one disruption cascades. They can stress-test: what happens if Hormuz closes for 30 days? What if Malacca follows?

Insurance underwriters price real risk instead of guessing. Energy traders pre-position inventory at strategic hubs. Manufacturers discover which tier-3 suppliers share the same chokepoint — a vulnerability invisible without the network view.

The Hormuz crisis was not a black swan. Networks with high betweenness centrality always carry concentrated risk. The question is whether your organization modeled it first.