By David Born
Maritime chokepoints — narrow straits and canals through which a disproportionate share of global seaborne trade is concentrated — are no longer a background variable in supply chain strategy. The 2026 closure of the Strait of Hormuz demonstrated how a single corridor disruption can cascade from an energy shock into petrochemical feedstock shortages and manufacturing stoppages across multiple continents. A 2025 Nature Communications study estimates USD 191.5 billion of global trade is statistically at risk of disruption each year, with three chokepoints accounting for 77% of actual economic losses. Disruption stems from three vectors: accidents, climate events, and geopolitical pressure. Organizations that have not quantified their chokepoint exposure at a granular level are operating with a structural blind spot in an environment where that risk is increasing.
1. Maritime chokepoints are the enabler for hyperglobalized supply chains by funnelling massive cargo volumes through narrow passages. Yet this very same concentration creates systemic risk by amplifying disruptions and their cascading effects across global supply chains.
2. Geography is increasingly wielded as a geopolitical asset, as states seek to leverage control over maritime chokepoints for economic gain and strategic influence.
3. Preparedness determines resilience in a crisis. Companies with alternative routes and contingency plans are better positioned to withstand sudden chokepoint closures and can reduce supply chain disruptions.
On February 28, 2026, US and Israeli forces launched coordinated strikes against Iran. Within days, commercial transit through the Strait of Hormuz had collapsed from over 100 vessels per day to fewer than ten — not through an immediate physical blockade, but because Iran made the waterway economically unviable first, withdrawing insurance coverage conditions before naval mines turned economic disruption into physical closure. Meanwhile, Iran-backed Houthi rebels completed their takeover of Yemen's entire Red Sea coastline, seizing Perim Island in the middle of the Bab al-Mandeb strait and positioning forces just 20 kilometres from the African coast. Two of the world's most critical maritime passages are effectively under siege at the same time.
The two episodes share the assertion of control over a narrow geographic passage — whether by state or proxy — with consequences that radiate across the global economy within days. What makes these episodes so consequential is not the actors involved, but the geography they are exploiting. That chokepoints exist is inevitable; that they are increasingly being leveraged against the flow of global commerce is a choice — and a growing one.
Approximately 80% of global merchandise trade volume moves by sea — not by design, but because maritime transport is, by orders of magnitude, the most cost-efficient mode of moving large volumes of goods across long distances. The economics of globalisation are inseparable from the economics of sea freight.
That efficiency, however, depends on a small number of geographic passages where the world's shipping lanes converge. These chokepoints — narrow straits and canals through which a disproportionate share of global seaborne trade is concentrated — are the structural constants of the trading system. They cannot be expanded, duplicated, and often also not bypassed at reasonable cost and speed. Our study examines the most strategically significant among the 28 chokepoints identified by the International Monetary Fund — the passages that together form the skeletal structure of global commerce.
What makes chokepoints systemically significant is not merely their traffic volume, but the intersection of three factors: the share of global trade they carry, the concentration of specific goods routed through them, and the absence of viable alternatives should they become impassable. When all three converge — high volume, high commodity concentration, and low substitutability — a disruption does not simply slow trade. It triggers a cascade: input shortages propagate upstream into production, finished goods are stranded downstream, and the economic damage surfaces far from the point of disruption, in industries and geographies that had no direct visibility into their own exposure.
The Hormuz crisis illustrated that transmission mechanism with unusual clarity. The first-order effect — an energy price shock — was widely anticipated after the first strikes. The second and third-order effects were not.
Crude oil, when refined, yields naphtha. Naphtha, when cracked, yields ethylene and propylene — the building blocks of plastics, synthetic fibres, packaging, and a vast range of industrial components. Because more than half of Asia's seaborne naphtha supply originates in the Gulf, the Hormuz closure became simultaneously an energy shock, a petrochemical feedstock shock, and a manufacturing inputs shock. Within weeks, producers in Japan, South Korea, Singapore, and Taiwan declared force majeure and idled production facilities. Yet the Gulf countries are not only relevant in energy products – they are also major exporters in fertilizers, agricultural products and metals. Automotive manufacturers in Europe scrambled to build aluminium inventories, knowing that qualifying alternative suppliers takes between six and twenty months. Aviation networks contracted as jet fuel supplies tightened.
This is the defining characteristic of chokepoint risk: concentrated at the source, diffuse at the point of impact. The naphtha shortage that idled South Korean petrochemical plants and the aluminium shortage that prompted European procurement acceleration both originated at the same 33-kilometre-wide waterway.
A landmark study published in Nature Communications in 2025 provides the most rigorous quantification of chokepoint risk to date. Drawing on historical event data and stochastic modelling across eight hazard categories — from tropical cyclones and drought to piracy, armed conflict, and interstate war — the authors estimate that USD 191.5 billion of global trade is statistically at risk of disruption each year. Actual economic losses are estimated at USD 10.7 billion per year, with three chokepoints accounting for 77% of that total: the Bab el-Mandeb Strait, the Suez Canal, and the Strait of Malacca.
Critically, the risk is not uniform. A chokepoint with high traffic volumes but credible rerouting options poses a manageable disruption risk. One that funnels a disproportionate share of a critical commodity through a passage with no realistic substitute represents a structural vulnerability of an entirely different order.
What distinguishes the current environment from previous episodes of supply chain stress is not the scale of any individual disruption, but the convergence of multiple risk vectors simultaneously — and the direction of travel.
The fracturing of the multilateral trade order, the growing willingness of state actors to instrumentalise geographic chokepoints as tools of leverage, and the acceleration of climate-driven operational risks all point in the same direction: chokepoint disruptions will become more frequent, more varied in their causes, and more difficult to anticipate. Indonesia's proposal to levy transit fees on vessels passing through the Strait of Malacca, Denmark's use of the Danish Straits to enforce sanctions on Russian shipping, and the United States' pressure on Panama over port concessions all illustrate the same underlying dynamic: geographic position is increasingly understood as a political and economic asset, and governments around the world are becoming more willing to act on that understanding.
For supply chain strategists, the implication is clear. The planning assumptions that governed supply chain design for the past three decades — stable maritime access, predictable freight costs, reliable just-in-time delivery — were calibrated for a world that no longer exists. Recalibrating for a world in which chokepoint risk is a core variable, not a tail risk, is no longer a strategic option. It is an operational necessity.
Understanding chokepoint exposure is the starting point, not the conclusion. Organisations that have mapped their procurement costs, revenues, and margins against specific maritime corridors — at stock-keeping unit level, not category level — are in a fundamentally different position when disruption strikes than those that have not. Pre-negotiated contingency freight capacity, risk-weighted inventory strategies, and supplier bases structured around chokepoint independence rather than geographic proximity are the instruments through which exposure becomes manageable.
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As geopolitical pressure and climate risk raise the likelihood of chokepoint disruptions, old rules of supply chain resilience no longer hold.
