Why The US Navy Needs Marines To Open The Strait of Hormuz

5:27 local time, the Persian Gulf, day 30.

Right now, as you’re watching this, roughly 150 freight ships are sitting dead in the water at one of the most critical choke points on the planet.

Oil tankers, LNG carriers, container ships, all of them stalled.

Uh, all of them waiting.

Another day, the straight of Hormuz remains closed.

not delayed, not partially restricted, closed, effectively shut down since March 4th, 2026 when the IRGC declared the straightoff limits to foreign shipping following US and Israeli air strikes on Iran.

20% of the world’s oil supply, 20% of the world’s liqufied natural gas gone.

And the United States operating the most powerful navy ever assembled is struggling to reopen it.

And here’s why.

The answer isn’t more destroyers, more carrier strike groups, or more air power.

The answer might be Marines.

Thousands of them aboard amphibious assault ships already steaming toward the Gulf.

Here’s what they’re going to have to do.

The Straight of Hormuz sits between Iran to the north and Omen and the UAE to the south.

At its narrowest point, it is 21 miles wide, 34 km.

For context, that is roughly the distance from downtown Manhattan to the New Jersey Turnpike.

But the actual navigable shipping lanes inside that gap are a fraction of that total width.

Two lanes, each 2 mi wide, separated by a 2m buffer zone.

That is the corridor through which a significant fraction of the world’s energy supply moves every single day or moved until March 4th.

In 2024, approximately 20 million barrels of oil transited the straight daily.

That translates to roughly $500 billion in annual energy trade passing through a gap you could drive across in under 30 minutes.

Through 2023 and into 2025, 20% of the world’s liqufied natural gas and 25% of all seaborn oil trade passed through that waterway every year.

And for three countries, Kuwait, Qatar, and Bahrain, the straight is not one of several options.

It is the only maritime exit they have.

There is no alternate route, no bypass, no workaround.

When the straight closes, those countries are landlocked by water.

Four operational pipeline systems exist that could theoretically carry Gulf oil overland and around Iran’s choke point.

Combined, they can handle somewhere between 3.5 and 5.5 million barrels per day.

The daily shortfall from a closed straight is between 14.5 and 16.5 million barrels.

There is no infrastructure on Earth that covers that gap.

When Iran shut the straight down, the world didn’t wait weeks to feel it.

It felt it in days.

Oil prices surged 10 to 13% in the first 72 hours.

By March 2nd, crude was trading at around $80 to $82 per barrel.

By late March, it crossed $100.

At peak, it hit $114 per barrel, the highest since the CO 19 pandemic.

The International Energy Agency called it in formal language that institutions rarely use the greatest global energy security challenge in history.

Europe was already vulnerable.

Heading into the crisis, the continent was sitting at just 30% gas storage capacity after a harsh winter.

Dutch TTF gas benchmarks nearly doubled to over €60 per megawatt hour by mid-March.

The European Central Bank postponed its planned interest rate cuts.

The IMF warned that every 10% increase in energy prices pushes global inflation up by nearly half a percentage point.

The consequences didn’t stay in financial markets.

Bangladesh closed universities early.

Pakistan and the Philippines declared 4-day work weeks.

Chemical and steel manufacturers across the UK and the EU imposed a product search charges of up to 30%.

This is what a closed straight of Hormuz does to the global economy.

Not in months, in weeks.

Here’s where most people assume the US Navy just escort ships through and calls it done.

It’s not that simple.

Not even close.

Iran’s closure strategy is not a single weapon or a single tactic.

It is a layered system of threats.

Each one designed to complicate the next.

And the whole architecture is built specifically to defeat the kind of response the US Navy is best equipped to deliver.

Start with the fast attack boats.

The IRGC operates large numbers of small, fast, heavily armed watercraft that move in coordinated swarms.

They are cheap to build and cheap to replace.

They are difficult to track from the air and nearly impossible to engage efficiently from large warships without exposing those warships to additional threats simultaneously.

Then there are the mines.

The US Defense Intelligence Agency estimated that Iran possessed over 5,000 naval mines as of its last comprehensive assessment.

Mines can be deployed rapidly from high-speed boats, from submarines, and from shore-based positions.

They are cheap.

They are covert.

They can be laid faster than they can be cleared.

Once a channel is mined, no amount of escort destroyers solves the problem because the threat is already in the water, invisible, waiting.

Air power can hit the fastboat staging areas.

Air power can strike mine laying vessels before they deploy, but air power cannot hold the coastline that overlooks the clearing operation.

To protect mine sweepers while they work, you need to control the terrain around them.

The islands are named Larak, Keshum, and Abu Musa.

They sit inside and around the straight itself.

They are not simply pieces of land.

They are armed positions, radar installations, missile launch sites, surveillance posts with line of sight coverage over the navigable lanes below.

The IRGC has spent years converting them into fortresses, specifically engineered to hold maritime traffic hostage without requiring a single Iranian warship to leave port.

Iran’s land-based anti-hship missile batteries run along a coastline that is mountainous, heavily fortified, and riddled with hardened underground infrastructure.

On March 17th, US Central Command employed multiple GBU72 5,000lb penetrator munitions against underground missile silos along the Iranian coast.

Weapons chosen precisely because the targets were buried under layers of rock and reinforced concrete.

Even after those strikes, Iran’s arsenal was not eliminated.

By March 5th, Iranian military sources told state media that the country had already fired over 500 ballistic and naval missiles and nearly 2,000 drones since late February.

Analysts noted Iran appeared to be rationing, holding reserves back for a longer campaign.

Air power can damage the island installations.

Air power can crater a missile silo, but air power cannot occupy Larak.

It cannot prevent rearming.

It cannot guarantee positions stay down after strike aircraft return to their carriers.

Air power can destroy.

It cannot hold.

That gap is what Marines are designed to fill.

And right now, they’re already moving.

On March 11th, 2026, the USS Tripoli departed Okinawa, Japan.

It is an America class amphibious assault ship 43,745 tons optimized for sustained aviation heavy marine operations at sea.

It carries F-35B fighter jets, MV22B Osprey Tiltrotor aircraft and CH53EC Stallion heavy lift helicopters.

Unlike older amphibious ships, the Tripoli has an enlarged hanger deck, expanded aviation fuel capacity, and no well deck.

Every design decision orients the ship toward continuous air operations.

Embarked aboard the 31st Marine Expeditionary Unit.

Approximately 2,200 Marines.

The Marine Corps is only continuously forward deployed MEU permanently based in Japan.

Pentagon officials simultaneously announced 2,500 additional Marines on route.

Following behind the USS Boxer carrying the 11th Marine Expeditionary Unit out of California, another 2500 Marines.

Supporting vessels include the USS New Orleans and USS Rushmore.

Combined Marine combat power converging on the theater between 4,700 and 5,000 personnel.

A Marine Expeditionary Unit is built around the Marine Airground task force MGTF.

Four fully integrated components, a command element, a ground combat element, an aviation combat element, and a logistics combat element.

The entire structure is designed to operate independently from the sea.

According to Marine Corps veteran Jonathan Hackett, a counterintelligence specialist who analyzed the deployment for the Jerusalem Post, the MEU is a self-contained combat force that does not rely on outside support to execute its expeditionary amphibious operations.

This is not one mission.

It is four running simultaneously.

The first coastal assault and island seizure.

The 31st MEU’s aviationheavy configuration, Sea Stallions, Ospreys, Viper Attack helicopters gives commanders the ability to conduct air assault operations onto terrain impossible to reach by sea under fire.

Sentcom confirmed on March 19th the deployment of A-10 specifically to strike fast attack watercraft and Apaches to handle one-way attack drones.

Marines provide the ground element that secures what the air campaign strikes.

The second mine countermeasure support.

Marines secure nearby coastlines so mine sweepers can operate without Iran receding cleared channels from shore.

Without that ground security layer, mine clearing operations proceed under constant unacceptable risk.

The third visit, board, search, and seizure.

Marines launch from the Tripoli, New Orleans, and Rushmore to intercept vessels suspected of carrying mines or weapons.

The MV22B Osprey allows teams to insert from standoff distance across a wide maritime area, mirroring operations conducted during 1988’s Operation Praying Mantis and 2003’s Operation Iraqi Freedom.

The fourth, seizure of strategic infrastructure.

Car Island handles approximately 90% of all Iranian oil exports.

AMU’s battalion landing team up to 550 personnel is specifically the force capable of seizing and holding infrastructure of that type with creating a direct economic bargaining chip that no air strike on a dispersed missile battery can replicate.

On March 19th, Sentcom launched the formal aerial campaign targeting Iranian naval assets.

Sentcom reported striking over 11,000 targets inside Iran since late February.

On March 26th, Israel announced it had killed IRGC naval commander Alerza Tangiri, the officer directly overseeing the blockade.

Iran replaced him within 48 hours.

Iran is not yielding.

By March 27th, the IRGC was still blocking vessels from countries it had previously announced would be permitted passage.

The United States presented a 15-point proposal via Pakistani intermediaries on March 24th.

Dismantle the nuclear program, end enrichment, surrender the stockpile, limit missiles, end proxy support, guarantee navigation.

Iran rejected it.

The White House threatened further military action on March 25th.

22 countries have signed a statement supporting measures to secure the strait.

Most NATO allies have declined direct participation.

The Navy can dominate the sea.

It can sink ships, launch strikes, and maintain air superiority over the Persian Gulf indefinitely.

That is not in question.

But naval dominance alone cannot reopen the straight of Hormuz.

Iran’s strategy was never designed to fight the US Navy in open water.

It was designed to make the straight too dangerous to transit through terrain, through mines, through landbased missiles buried under rock and concrete, through cheap asymmetric tools specifically engineered to impose costs that conventional naval power cannot efficiently eliminate.

Every layer of that strategy points to the same requirement.

You have to take the ground.

That is not a destroyer mission.

That is not a carrier strike group mission.

That is a marine mission.

And that is exactly why nearly 5,000 Marines are currently steaming toward one of the most dangerous and consequential bodies of water on Earth.

Because the Navy, for all its power, needs boots on the ground to open a straight that controls a fifth of the world’s energy supply.

The question isn’t whether they can do it.

The question is what it costs to find