Persian Gulf shipping under attack as US-Iran war spreads to commercial tankers

Overview

For decades, the global economy has treated the Strait of Hormuz as a reliable pipeline: one-fifth of the world's oil passes through a 21-mile-wide channel between Iran and Oman every day. Five days into the US-Iran war, that pipeline is shut. An Iranian drone boat struck the Suezmax tanker Sonangol Namibe on March 4 while it sat at anchor 30 nautical miles off Kuwait's coast, breaching the hull and sending oil into the water. It was the largest commercial vessel attacked and the farthest north any strike has reached since hostilities began on February 28.

In This Story

3 Videos

2 People

3 Orgs

9 Events

5 Key Stats

4 Scenarios

US Navy begins convoy escorts; strait partially reopens under military protection

3 Context

Iran-Iraq Tanker War and Operation Earnest Will (1981-1988)

Key Indicators

Daily Strait of Hormuz transits

Traffic through the strait dropped from normal levels to near zero within days, down approximately 90% from pre-conflict volume.

20,000

Stranded seafarers

The International Maritime Organisation has warned of a humanitarian crisis for crew members trapped aboard vessels inside the Gulf.

~200

Tankers trapped in the Gulf

Including at least 40 very large crude carriers, each carrying roughly 2 million barrels of oil, now idling with no safe route out.

$84+/bbl

Brent crude price

Oil prices rose over 10% in the first days of the conflict, with analysts warning of $100-plus if disruptions persist.

20%

Global oil supply at risk

The Strait of Hormuz handles roughly one-fifth of global petroleum consumption and one-fifth of liquefied natural gas trade.

Interactive

Exploring all sides of a story is often best achieved with Play.

Ever wondered what historical figures would say about today's headlines?

Debate Arena

Two rounds, two personas, one winner. You set the crossfire.

People Involved

Alireza Tangsiri

Commander, Islamic Revolutionary Guard Corps Navy (Directing IRGC naval operations in Persian Gulf)

Donald Trump

President of the United States (Ordered strikes on Iran; pledged insurance and Navy escorts for Gulf shipping)

Organizations Involved

Islamic Revolutionary Guard Corps (IRGC) Navy

Military Force

Status: Actively attacking commercial shipping and enforcing Strait of Hormuz closure

Iran's parallel naval force specializing in asymmetric warfare, operating thousands of fast boats and drone vessels in the Persian Gulf independently from the conventional Iranian navy.

UK Maritime Trade Operations (UKMTO)

Maritime Security Advisory Body

Status: Issuing critical-level advisories for the Persian Gulf

The UK Royal Navy's primary point of contact for merchant vessels operating in the region, issuing real-time security alerts and coordinating responses to maritime incidents.

Sonangol

State-Owned Oil Company

Status: Owner of the attacked vessel

Angola's state oil company and owner of the Sonangol Namibe tanker, which operates in a pool managed by Sweden-based Stena Bulk.

Timeline

International Maritime Organisation warns of humanitarian crisis
Humanitarian

The IMO warned that 20,000 seafarers and 15,000 cruise passengers were stranded in the Persian Gulf, with crew members unable to be evacuated from vessels trapped in a war zone.
Today
Drone boat strikes Sonangol Namibe tanker off Kuwait, causing oil spill
Attack

An explosive-laden drone boat detonated against the port side of the Bahamas-flagged Suezmax tanker Sonangol Namibe while it sat at anchor 30 nautical miles southeast of Kuwait. The blast breached the hull and caused oil to leak into the water. It was the largest vessel attacked and the northernmost strike since hostilities began, extending the threat zone deep into the Persian Gulf.
Yesterday • 22:40 local (Mar 4)
IRGC claims complete control of Strait of Hormuz; only five transits recorded
Escalation

The IRGC announced full control of the strait. Satellite tracking data showed just five vessel crossings for the entire day, down from hundreds under normal conditions.
2 days ago
Trump orders government-backed shipping insurance, offers Navy escorts
Policy

President Trump directed the US Development Finance Corporation to provide political risk insurance for all maritime trade in the Gulf. He said the US Navy would escort tankers through the Strait of Hormuz if necessary. No convoy had yet sailed by March 5.
3 days ago
IRGC declares Strait of Hormuz closed, threatens to attack transiting ships
Escalation

A senior IRGC official confirmed the strait was closed and threatened to "set ablaze" any vessel attempting to pass. Tanker traffic dropped approximately 70%, with over 150 ships anchoring outside the strait. Major shipping lines including Maersk, Hapag-Lloyd, and MSC halted Gulf transits.
4 days ago
Major insurers cancel war-risk coverage for the Persian Gulf
Economic

Leading maritime war-risk underwriters withdrew coverage for vessels operating in the Persian Gulf. Premiums that had already risen from 0.125% to 0.4% of insured hull value became unavailable entirely. Without insurance, shipping companies cannot legally operate.
4 days ago
First tanker attacks hit three vessels near the Strait of Hormuz
Attack

The Palau-flagged tanker Skylight was struck 5 nautical miles off Oman, injuring four crew. The crude carrier MKD Vyom took a projectile hit that caused an engine room fire and killed one crew member. A third vessel, the Sea La Donna, also reported an incident.
5 days ago
US and Israel launch Operation Epic Fury against Iran
Military

Coordinated airstrikes hit Iranian military facilities, nuclear sites, and leadership targets across Tehran, Isfahan, Qom, and other cities. Supreme Leader Ali Khamenei was killed.
6 days ago • 02:30 EST
Iran retaliates with missiles and drones across the region
Military

Iran launched Operation True Promise IV, firing missiles and drones at US military bases in Kuwait, Bahrain, Qatar, Iraq, Saudi Arabia, and the UAE, as well as at targets in Israel. The IRGC warned all vessels against transiting the Strait of Hormuz.
6 days ago

Scenarios

US Navy begins convoy escorts; strait partially reopens under military protection

Discussed by: USNI News, Bloomberg, and maritime analysts drawing parallels to Operation Earnest Will (1987). The Trump administration has already announced the legal framework via the DFC insurance order.

The US Navy organizes convoy escorts through the Strait of Hormuz, similar to Reagan-era reflagging operations during the 1980s tanker war. With government-backed insurance replacing commercial coverage and warships accompanying tankers, some shipping companies resume transits. Oil prices stabilize but remain elevated due to reduced throughput and the risk of Iranian mines or fast-boat attacks on convoys. This scenario depends on the US Navy having sufficient minesweeping capability to clear the strait and the political willingness to risk a direct naval confrontation with the IRGC.

Strait remains closed for weeks; oil prices spike above $100 as strategic reserves deploy

Discussed by: Energy analysts at Goldman Sachs and JP Morgan, CNBC, and the International Energy Agency. Analysts note that global strategic petroleum reserves, while substantial, cannot replace 20 million barrels per day of Gulf throughput indefinitely.

IRGC mining of the strait and continued drone-boat attacks prevent any reopening despite US military presence. Countries dependent on Gulf oil, particularly China, India, Japan, and South Korea, draw down strategic reserves while scrambling for alternative supply. Brent crude climbs past $100 per barrel. Global recession fears intensify as energy costs cascade through supply chains. This scenario is most likely if Iran successfully deploys sea mines across the shipping lanes, which US minesweeping operations would take weeks to clear.

Ceasefire or diplomatic deal halts attacks; shipping resumes within days

Discussed by: European foreign ministers, UN Security Council discussions, and Gulf Cooperation Council mediators. China, as the largest buyer of Gulf oil, has a direct interest in brokering a halt.

International pressure, particularly from oil-importing nations facing economic damage, produces a ceasefire or narrow agreement covering maritime traffic. Iran, having demonstrated its ability to close the strait, extracts concessions in exchange for reopening it. Shipping resumes gradually as insurers reinstate coverage. This scenario becomes more plausible if Iran's conventional military capacity is degraded enough that continued attacks become unsustainable, or if regime survival calculations shift under new leadership following Khamenei's death.

Attacks spread to Gulf state ports and energy infrastructure, widening the war

Discussed by: Flashpoint intelligence assessments, CSIS analysis, and Pentagon briefings. The Sonangol Namibe attack deep inside the Gulf already signals geographic expansion.

Iran escalates beyond targeting ships in transit, striking port facilities, oil terminals, and desalination plants in Kuwait, Saudi Arabia, and the UAE. The conflict widens from a maritime chokepoint dispute into a broader regional infrastructure war. Gulf states, initially bystanders, are drawn into direct confrontation. Energy markets enter crisis as not just transit but production capacity comes under threat. The northward creep of attacks, from the Strait of Hormuz to waters off Kuwait, suggests this escalation pathway is already underway.

Historical Context

Iran-Iraq Tanker War and Operation Earnest Will (1981-1988)

1981-1988

What Happened

During the Iran-Iraq War, both sides attacked commercial shipping in the Persian Gulf to choke off each other's oil exports. Over seven years, 411 ships were attacked, 239 of them oil tankers, killing more than 400 civilian sailors. Iraq used fighter jets armed with Exocet missiles; Iran deployed small boats and naval mines.

Outcome

Short Term

In 1987, the Reagan administration reflagged 11 Kuwaiti tankers as US vessels and deployed over 30 warships to escort convoys under Operation Earnest Will. On the first escort mission, the tanker MV Bridgeton struck an Iranian mine.

Long Term

The operation succeeded in keeping oil flowing despite Iranian attacks, but at the cost of the USS Samuel B. Roberts striking a mine and the US Navy accidentally shooting down Iran Air Flight 655, killing 290 civilians. The precedent of US Navy convoy escorts is now directly informing the Trump administration's response.

Why It's Relevant Today

Trump's March 3 announcement of Navy escorts and government-backed insurance directly mirrors Reagan's 1987 playbook. The 1980s tanker war also demonstrated that even a major naval presence cannot fully prevent mine attacks and small-boat harassment in the Gulf's confined waters.

Gulf of Oman tanker attacks (2019)

May-June 2019

What Happened

Six commercial vessels were damaged in two separate incidents near the Strait of Hormuz in May and June 2019. The US attributed the attacks to Iran, pointing to video footage appearing to show IRGC personnel removing an unexploded limpet mine from the hull of the Japanese-owned tanker Kokuka Courageous. Iran denied responsibility.

Outcome

Short Term

Oil prices spiked temporarily and war-risk insurance premiums rose, but shipping continued through the strait. The US formed the International Maritime Security Construct, a multinational naval patrol coalition.

Long Term

The attacks demonstrated Iran's ability to threaten Gulf shipping through deniable asymmetric tactics without triggering a major military response. They established a template for exactly the kind of escalation now playing out at a far larger scale.

Why It's Relevant Today

The 2019 attacks were probing operations: small-scale, deniable, and designed to demonstrate capability without crossing a threshold for military response. The current wave of attacks has abandoned deniability entirely, with the IRGC openly claiming control of the strait. The shift illustrates how a full-scale military confrontation has removed Iran's incentive for restraint.

Houthi Red Sea shipping attacks (2023-2025)

November 2023 - 2025

What Happened

Yemen's Houthi forces, an Iranian-backed group, launched over 100 attacks on commercial shipping in the Red Sea and Gulf of Aden using missiles, drones, and explosive boats. The attacks forced major shipping lines to reroute vessels around the Cape of Good Hope, adding 10-14 days and significant costs to Asia-Europe trade routes.

Outcome

Short Term

A US-led naval coalition, Operation Prosperity Guardian, failed to stop the attacks. Container shipping rates between Asia and Europe tripled at their peak. War-risk insurance premiums for Red Sea transit climbed to historic levels.

Long Term

The Houthi campaign proved that a militarily modest force could disrupt global shipping lanes for an extended period despite the presence of advanced naval forces. Insurance markets, not military escorts, became the binding constraint on commercial shipping.

Why It's Relevant Today

The Red Sea precedent showed how insurance withdrawal, more than physical danger, can shut down a shipping lane. The same dynamic is now playing out in the Persian Gulf at far greater economic consequence. The Houthi attacks also demonstrated that drone boats and missiles can overwhelm naval defenses when launched from multiple vectors, a lesson the IRGC appears to be applying.