When global sea routes become battlefields

Highlights:

• Maritime chokepoints increasingly weaponised in geopolitical conflicts, threatening global trade
• Strait of Hormuz tensions endanger vital global oil and gas supplies
• Red Sea and Black Sea conflicts disrupt shipping and raise costs
• UNCLOS protections struggle against geopolitical disputes and weak enforcement
• Bangladesh faces higher freight costs, delays, and energy supply risks
• Disrupted sea routes fuel inflation and threaten global food security

For decades, the world's busiest maritime chokepoints were governed by a simple principle: ships carrying global trade should pass freely, regardless of politics.

That principle is being tested as never before. From the Red Sea and the Black Sea to the Panama and Suez canals, strategic sea routes have increasingly become bargaining chips in geopolitical conflicts, exposing the fragility of the international rules designed to keep global commerce moving.

Infograph: TBS

The latest tensions over the Strait of Hormuz, through which around one-fifth of the world's oil and gas supplies pass, reinforce a troubling pattern. As conflicts spread from one maritime corridor to another, an increasingly important question emerges: are existing international laws sufficient to protect global shipping, or are they no longer enough to keep vital sea lanes open?

The world's trade arteries under pressure

The Strait of Hormuz was safe and stable until the US-Israel war on Iran in February this year. One of the world's most important oil chokepoints, the strait links the Persian Gulf with the Gulf of Oman and the Arabian Sea. Any disruption on this route hits Asian countries the first and the most because of their heavy reliance on the Middle East to meet energy needs. For Bangladesh, the crisis is more acute as it relies on Hormuz and Bab el Mandeb straits to ship its most energy and fertiliser supplies from Middle Eastern sources.

Similarly, vital maritime corridors Black Sea and Red Sea are vulnerable to wars and conflicts, leading to restrictions or shutdown, heavily disrupting trade flows. Bangladesh, like many other countries, suffered badly as supplies of wheat, fertilisers and chemicals dwindled when Black Sea was blocked due to the Russia-Ukraine war in 2022. Shipments from Bangladesh to Europe faced higher freight costs and longer routes when shipping through the Red Sea was disrupted due to attacks on ships by Houthis in 2024.

Both the sea corridors have again turned unreliable for global shipping.

As the Hormuz stalemate drags on, a new front opened on the Red Sea as Iran-aligned Houthis fired missiles at a Saudi oil tanker, prompting many global shipping lines to avoid this route. Navigation in Russia's Black Sea waters has again turned dangerous after Ukraine intensified attacks on Russian shipping.

Weaponising of sea corridors, which include natural narrow sea routes and man-made canals, is not new in history despite international laws and conventions to keep sea trade safe and undisrupted. The Suez Canal, controlled by Egypt, was heavily impacted by three major wars involving Egypt, Israel, Britain, France and some Arab states since the 1950s, causing eight years of shutdown in one instance.

Panama, which got absolute rights over the Panama Canal from Americans decades back, still faces US pressure for strong Chinese presence.

Hormuz tests the limits of UNCLOS

Unlike canals which are artificial and controlled by individual countries, natural straits are treated as global commons for shipping. As per international law, coastal countries are not supposed to charge toll for transiting the straits, though some are charging "voluntary contributions".

The rules on global shipping and navigation under the United Nations Convention on the Law of the Sea (UNCLOS) promise to ensure innocent passage or transit passage through international straits free of charge. But conflicts often put those laws aside as now seen in Hormuz.

Control of the strait remains a main sticking point in efforts to resolve the US-Iran war, which does not seem to be ending soon since the interim ceasefire deal agreed in June is now ineffective and repeatedly broken.

Amid US intention to act as the "guardian" of the Strait of Hormuz and resume its naval blockade against Iranian ports and shipping lanes, Iran effectively shut the strait to consolidate its control over the strategic waterway. Iran has asserted its sovereign right to manage the strait and collect fees for unspecified services along with Oman, while Washington insists any mandatory fees would violate international law governing transit through international straits.

On Tuesday, Oman came up with a plan envisaging regional management of the strait and collection of voluntary fees. Oman's plan appears similar to arrangements in the Strait of Malacca, with coastal nations Indonesia, Malaysia and Singapore agreeing to keep the waterway free and safe for global trade while asking ships to pay voluntary contributions to fund navigation, environmental protection and search-and-rescue operations.

But for sea trade, security matters more than any such fees, though it is not often guaranteed as sea routes are exposed to geopolitical conflicts and wars.

Conflict comes at a global cost

Extensive data from organizations like UN Trade and Development (UNCTAD) shows that conflicts at key maritime chokepoints – such as the Red Sea, Suez Canal, and Strait of Hormuz – cause massive trade drops, billions in economic losses, longer ship routes around Africa, and higher fuel, insurance, and consumer prices.

Ship tonnage through the Suez Canal and Gulf of Aden dropped by over 70% during recent Red Sea conflicts as vessels avoided the area. Ships forced to bypass the Suez Canal and travel around the Cape of Good Hope add 10 days or more to a standard journey, increasing global ship ton-miles by nearly 6%.

Quantitative studies estimate global losses of $10.7 billion per year in delays and rerouting, plus an extra $3.4 billion annually in elevated freight costs.

The latest attack in the Red Sea has already started to cost Bangladesh's shipments heavily.  

A shipment of Saudi Arabian crude oil had to avoid the Red Sea and Bab el Mandeb strait, and sail via the Strait of Gibraltar and South Africa's Cape of Good Hope due to security risks. The 9,000-nautical-mile detour around Africa could delay the delivery by a month and add around $5million in freight cost, while adding to the persisting energy problem. The Red Sea is vital for Bangladesh's trade with Saudi Arabia, which is also a major source of fertilizer apart from crude oil.

Bangladesh's exporters are complaining about booking delays and higher costs as mainline operators are citing that security fears and restrictions in key sea corridors limited ship movements, leading to shortage of ships.

Worldwide impacts are far worse than what data shows. War-risk shipping insurance premiums and fuel expenses spike dramatically during active conflict, feeding directly into higher global consumer inflation and food prices.

The world has built its trading system on the assumption that international sea lanes will remain open even during periods of political tension. That assumption is becoming increasingly fragile. Every disruption – whether in the Suez Canal, the Red Sea, the Black Sea or now the Strait of Hormuz – raises shipping costs, fuels inflation and threatens energy and food security far beyond the conflict zone.

The problem is no longer the absence of international rules. It is the absence of effective enforcement when those rules collide with geopolitical interests. Unless major regional and global powers find stronger mechanisms to protect maritime chokepoints from becoming instruments of coercion, global trade will remain vulnerable to recurring disruptions whose costs are ultimately borne by consumers worldwide.