Why Trump Enforced A Naval Blockade In Strait Of Hormuz

Washington : The US blockade on Iranian ports is aimed to curb Iranian energy exports, thereby crippling its economy to force Iran back to the negotiating table, points out Commodore Venugopal Menon (retd).

US navy blockade in Strait of Hormuz targets Iranian oil exports, aiming to weaken Tehran's economy without full-scale war escalation.

Naval blockades involve complex operations including monitoring, interdiction, and enforcement, often facing legal scrutiny under international maritime law.

Iran has responded by asserting control over shipping routes, creating a de facto maritime exclusion zone in the strategic chokepoint.

High traffic density, asymmetric threats, and logistical constraints make enforcement of a blockade in narrow straits extremely challenging.

Global energy supply chains face disruptions, with rising freight costs, insurance premiums, and broader economic uncertainty due to tensions.
 
The media is abuzz with the blockade implemented by the US navy in the Strait of Hormuz.

There are mixed narratives emanating from the US and Iran projecting contradictory statements with the former highlighting the achievement of blockading Iranian ports and the latter claiming unilateral control over the movement of ships to and from the Strait.

There are also reports about the Islamic Revolutionary Guard Corps (IRGC) allowing friendly countries to transit through the Strait after seeking the IRGC's permission and even total closure of the Straits as on April 18.

The truth, however, lies hidden in the fog of war.

Naval blockades are an act of war and are complex strategic operations that involve significant operational, legal and economic challenges, with the aim to restrict maritime access to target a nation's coast and cripple its economy or military capability.

Modern blockades are rarely total and focus on specific goods, requiring constant monitoring of high traffic areas and creating high risks of escalation.

A blockade works by positioning warships and aircraft/helicopters around an adversary's coast. Submarines also can be deployed in open oceans to achieve the objective.

In the West Asia context, the aim of the US navy is to restrict tankers carrying crude oil leaving Iranian ports and vessels entering the ports to load cargo thus weakening their economy without a full-scale invasion.

Close Blockade: This is an operation involving highest risk to the blockading force as they operate continuously at sea near the enemy coast, vulnerable to surface, underwater and air threats from the adversary.

The current US implemented blockade can be classified as a close blockade.

Distant Blockade: A safer approach for the blockader is to implement a blockade at a distance from the objective area.

This operation would be undertaken in open ocean and require many units to implement the intent.

Any blockade that the US navy would attempt at the seaward entrance of the Strait of Hormuz (Gulf of Oman/Oman Sea) would fall in this category.

Loose Blockade: A close blockade that positions behind the horizon to bait the adversary into exiting the port with the aim of intercepting the target using the element of surprise.

Total Blockade: The most severe form designed to completely shut down all entry/exit to a region.

Paper Blockade: A blockade that is announced but not effectively enforced is referred to as a paper blockade which is invalid under international law.

Establishment & Monitoring: Naval forces establish patrol zones, deploying ships, aircraft/helicopters using radar and other sensors, satellite imagery and aerial surveillance to identify and monitor vessels in the area.

Interdiction: Blockading forces intercept, board and search incoming/outgoing ships. Enforcement: Ships deemed to be violating the blockade are either turned back, boarded, or seized.

Economic warfare: Starve the adversary of critical resources (oil, food and essential goods) to paralyse their economy and livelihood.

Military Restriction: Prevent supplies, troops and weapon systems from reaching the adversary. Psychological Pressure: Demoralise the adversary's population and government by showcasing total isolation.

The US intent is to sever Iranian oil exports and penalise Tehran for interfering with maritime traffic in the Strait of Hormuz, following failed ceasefire negotiations.

The Strait of Hormuz is not controlled by a single entity: It is legally bordered by Iran and Oman, which hold sovereign rights over their coastal waters, but international law guarantees transit passage for global shipping.

Under international law (UNCLOS: United Nations Convention For Law of the Sea) both Iran and Oman control up to 12 nautical miles of sea room from their coastline.

During this conflict, Iran has turned this shared maritime route into a controlled area by attempting to regulate and even charge tolls on vessels passing through the Strait.

Maritime Exclusion Zone is closely linked to a blockade : As of April 2026, and as a counter to the US blockading Iranian ports, the Strait of Hormuz is experiencing a severe, de facto maritime exclusion zone with Iranian forces restricting or blocking commercial ships from transiting through the Strait of Hormuz in response to the US actions.

This action is legally contentious under the UNCLOS and Iran has imposed operational restrictions forcing vessels to follow alternate routes approved by the IRGC.

The blockade differs from a MEZ (Military Exclusion Zone) in that the former involves blocking or even confiscating a target vessel carrying prohibited cargo whereas the latter aims to attacking the target vessel.

Blockades are strictly regulated under international law, and it must be effective, declared and impartial.

MEZ is generally not the subject of an explicit treaty and is often treated as a zone of danger.

Also, under international law, a MEZ does not inherently allow the use of force against neutral ships outside territorial waters.

In modern context, a MEZ has largely replaced the physical blockade allowing for larger area coverage and better efficiency.

MEZ can also be declared prior to enforcing a formal blockade. Naval blockades are complex, high stakes maritime operations that function as a form of economic warfare.

Their execution involves significant logistical, legal and operational challenges often subjected to intense international scrutiny and severe economic impact on global shipping.

Enforcement Challenges: Enforcement of a naval blockade in the Strait of Hormuz implies severe operational, legal and economic complications. It requires huge manpower and resources.

These waterways are crucial for global trade and restricting movement of ships leads to rapid escalation of conflicts, intense logistical challenges for the blockading force and major disruptions to the global energy supply.

The current blockade in the Strait of Hormuz face additional challenges of heavy maritime traffic where it is impossible to board, inspect and redirect every ship in such a manner that smooth movement of trade is not affected.

The sheer volume of commercial traffic makes it nearly impossible to stop every vessel for investigation.

Dark fleet/Ghost ship problem: Non cooperative vessels frequently use GNSS (Global Navigation Satellite System) spoofing, false port records, false cargo manifest, false vessel registration records and AIS (Automatic Identification System) blackouts to evade detection and identification.

Asymmetry of Naval strength: An effective blockade is only feasible when the blockading power has a vastly superior naval force compared to the opponent.

In the current scenario, the US has a superior force undoubtedly, but this force is vulnerable to mines, unmanned craft attacks, shore based anti-ship missile batteries to name a few.

Narrow straits allow defenders to use swarm tactics with small fast attack crafts which are difficult to counter.

Limited Maneuvering Room: Blockading US force have limited space in the Strait to maneuver increasing the danger of accidents due to the restricted sea room.

Logistics difficulties: Sustenance of ships and crew at sea for long periods far from shore support makes the operation logistically complex.

Mine Warfare: The deployment of naval mines ranging from contact based to advanced magnetic, acoustic, pressure and combinations makes detection difficult and presents severe danger to all ships.

This threat can only be countered by specialised mine countermeasures operations which is slow and time consuming.

Legality: A blockade must be formally declared, officially notified and applied with impartiality.

Neutrality Rights: Interdiction of neutral ships can create huge legal risks for ship owners as it leads to conflict with international freedom of navigation principles elaborated in UNCLOS.

Humanitarian Concerns: Blockades that cause severe civilian starvation or violate humanitarian law (blocking food/medical aid are regarded as illegal.

Chokepoint sensitivity: Blockades in vital navigational straits such as Hormuz directly impact global energy supplies and disrupt the movement of vital cargo such as fertilizers and essential goods.

Rising Freight Costs: Insurance premiums often spike to prohibitive levels due to war risk insurance and commercial ships are forced to take longer routes thereby increasing fuel consumption resulting in high freight costs.

Supply Chain Disruptions: Even a partial blockade can cause severe port congestion and threaten global food and economic security to the region.

Effectiveness: Blockades rarely produce immediate results and are often used as tools for gradual economic pressure rather than swift military victory.

Substitution by alternate modes: Targeted nations find ways to import/export through alternate sources by land routes limiting total isolation the blockade seeks.

Might is Right Scenario: If the enforcing power is not bound by or ignores UNCLOS, the enforcement becomes a geopolitical contest reducing the effectiveness of international law and third-party intervention/mediation.

The US has embarked this conflict with multiple aims and objectives viz destroying Iran's nuclear infrastructure and enrichment capability, seizing uranium stockpile, capping their nuclear programme, destroying missiles/drone stocks and the ability to replenish them and cutting off Iran's support to proxy groups in the region.

Although these facets may not directly impact the effectiveness of the blockade, but indirectly it may determine the duration of the blockade.

Also, execution of multiple aims in a conflict may stretch the availability of resources and logistics that is paramount to achieving an effective blockade.

Effectiveness of a blockade is also indirectly linked to the third front war between Israel and Lebanon, total lack of international support to the US operations and the lack of convergence on the terms/conditions projected by the US and Iran in peace negotiations.

The US blockade on Iranian ports is aimed to curb Iranian energy exports, thereby crippling its economy to force Iran back to the negotiating table.

While the US navy has successfully intercepted vessels and maintained a firm presence, success remains uncertain as the blockade hinges on high stakes with global ramifications which could lead to a long-term war of attrition.

Iran has retaliated by closing the Strait and attempting to maintain its own control over ship traffic.

The current situation involves significant military risks with potential for further escalation unless and until both sides agree to reach a consensus during future peace negotiations.

Commodore Venugopal Menon served in the Indian Navy for 29 years in operational roles, including commands at sea, and training and staff assignments at Naval HQ.

In addition to the staff and war courses in the Indian Navy, he underwent the executive course at the Asia Pacific Centre for Security Studies, Honolulu.