The global food system is built on a premise that is often hidden yet fundamental: the sea. Today, about 80% of the world’s trade by volume moves by ship. In this vast logistical flow, we find wheat, corn, soy, vegetable oils, refrigerated food, farming seeds, and fertilizers. These are all essential for global food production and consumption.

Global food safety is strictly connected to the stability of sea routes¹. However, the international maritime traffic is not evenly distributed in seas and oceans. A significant number of ships are, in fact, forced to transit through quite narrow geographical passageways, known as chokepoints or bottlenecks, where maritime traffic is forced to converge. These obligated passages concentrate great volumes of traffic in limited spaces and represent structurally vulnerable points of the global trade system. In the case of war, accidents, piracy, extreme climatic events, or political crises, even a temporary interruption of one of these intersections/hubs can provoke chain effects that propagate quickly along the global logistic chains. As a result, we see a rise in transportation costs, delayed shipping, commodity market volatility, and pressure on the prices of food products.

A study published in Nature Communications magazine has highlighted how the interruption of the main chokepoints constitutes a systemic risk in the global economy, generating losses exceeding 10 billion dollars a year, including delays, route deviations, higher insurance costs, and supply chain ²disruptions.
For this reason, institutions and research centres constantly monitor the status of these strategic passages. For example, the United Nations Trade and Development (UNCTAD) analyzes the effects of geopolitical and logistical crises on global trade and food systems, while the Environmental Change Institute at the University of Oxford studies the vulnerability of chokepoints through monitoring platforms such as PortWatch³.

How many chokepoints are there, and what is their impact on the food system? Firstly, each of them does not have the same weight in the global trade. Some chokepoints assume particular relevance because of their geographical position and the volume of strategic materials that pass through these points. Among these, some are decisive for the stability of the global food system.

The first is the Strait of Hormuz, probably the most sensitive area in the world, being the beating heart of the global energy system. Every day, almost a quarter of the global petrol and a meaningful amount of the liquefied natural gas pass through this strait. However, its importance is not just connected to energy. More than 30% of the global nitrogen fertilizer, such as urea and ammonia, crosses this passage⁴. Recent events connected to the tension in the Middle East have shown the frailty of this hub: the daily reduction of traffic from about 95 ships to less than 10 has provoked the rapid rise in the price of urea, gone from about 450 to 600 dollars per ton in less than a week⁵. Furthermore, the analysis by UNCTAD highlights a historical correlation between floating energy prices and the Food Price Index, proving how the energy and fertilizer cost trend translates rapidly into pressure on food price⁶.

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A second critical area is Bab el-Mandeb, which connects the Red Sea to the Indian Ocean. This passage is one of the major trade arteries between Europe and Asia, and is particularly exposed to piracy and geopolitical instabilities, as drone and rocket attacks launched by the Houthis militia in the Red Sea against commercial vessels, starting from 2023⁷. Significant quantities of cereals, refrigerated foods, and fertilizers pass through Bab el-Mandeb, directed to the European and Mediterranean markets. Economic studies show that interruptions in this area correspond to significant global economic losses, connected to logistical blocks⁸.

A third strategic hub is the Suez Canal, one of the most important artificial passages of global trade. The container ship Ever Given incident in March 2021 has become a case point of the vulnerability of this system. For six days, the traffic in the canal came to a halt, causing hundreds of ships to queue and resulting in delays that affected supply chains worldwide. Even if an accidental incident and not the result of conflicts or external shocks, this event has shown how rapidly logistics can be compromised when one of the main chokepoints stops operating⁹.

Another fundamental passage is the Panama Canal, which connects the Atlantic with the Pacific Ocean and represents a crucial hub for agricultural exportation from America to Asia. In recent years, this chokepoint has become increasingly vulnerable to climate change. Prolonged droughts, amplified by the climate cycles of El Niño, have lowered water levels in the basins that provide water to the lock system, forcing the Canal Authority to limit the number of daily transits. That has had a direct impact on USA food exportation, namely soy and corn destined to Asian markets, demonstrating how climate variables make this chokepoint more unstable¹⁰.

And finally, the Bosphorus and Dardanelles Straits are of great importance, serving as the maritime gateway for grain from the Black Sea to the Mediterranean. Over 10% of global grain exports, primarily from Russia and Ukraine, pass through these straits. Geopolitical tensions can rapidly influence international cereal prices and the block of the so-called grain corridor in the Black Sea¹¹.

What happens when a chokepoint enters crisis? The effects follow a relatively clear and predictable sequence. The first impact concerns the rise in transportation costs and the insurance premiums for ships sailing through high-risk areas. Because of recent tensions in the Persian Gulf, many maritime companies have suspended navigation through the Strait of Hormuz, choosing alternative routes, which has resulted in a substantial increase in navigation times and costs. To such an increase, they often add an immediate rise in energy prices, since petrol and gas react rapidly to the tensions in the main export routes. Since the modern food system strongly depends on energy (for the production of fertilizers, the functioning of agricultural machinery, and the transportation of goods), the fluctuations in energy markets are rapidly reflected in food prices.

Another effect directly affects fertilizers and agricultural goods. For example, the recent crisis in the Strait of Hormuz caused a 30% increase in urea prices over a couple of days. Looking ahead, rising fertilizer costs tend to translate into lower agricultural yields or higher food prices in the months to follow. Finally, in countries heavily dependent on seaborne imports, problems with the physical availability of food may also arise. For example, many Gulf states import between 80% and 90% of the food consumed by their populations. In these contexts, a prolonged blockage of sea routes can quickly lead to shortages and tensions in domestic markets.

Recent crises—from tensions in the Middle East to attacks in the Red Sea, from drought in the Panama Canal to the Ever Given incident—clearly demonstrate how the architecture of the global food system depends on a few particularly vulnerable sea lanes. Chokepoints aren’t just a logistical problem: they also pose a strategic risk to global food security. When a stretch of sea just a few dozen kilometres wide ceases to function, the impact ripples throughout the global system: from fertilizers to grains, from livestock feed to meat production, and ultimately to the prices consumers pay in supermarkets.MalderaUnderstanding the centrality of these maritime hubs is therefore essential to designing more resilient food security policies. This involves investing in alternative logistics infrastructure, improving the monitoring of sea routes, strengthening international cooperation on navigation safety, and developing supply systems less dependent on a few critical points. In a world characterized by growing geopolitical tensions and increasingly unmistakable climate change, the resilience of the global food system will inevitably also depend on the ability to protect and manage these few, but crucial, kilometres of sea.

Luca Galantini

Marco Maldera