The maritime world just got turned upside down. On Monday, July 13, 2026, U.S. President Donald Trump took to Truth Social and Fox News to announce a radical shift in American foreign policy. The United States is reinstating its naval blockade on Iran. Even more surprising, Trump announced that the U.S. will start charging a 20% fee on all cargo moving through the Strait of Hormuz.
Calling the U.S. the new "Guardian of the Hormuz Strait," Trump argued that other wealthy nations must reimburse America for keeping this highly volatile waterway safe. It is a bold, transactional approach to global security that aligns perfectly with his established policy playbook. But it is already hitting massive legal, economic, and military walls.
If you are trying to understand why this matters, the answer is simple. Nearly a fifth of the world's oil passes through this narrow stretch of water. Any sudden attempt to charge a massive premium or restrict transit doesn't just hurt Iran. It shakes the foundations of global trade.
The Reality of the New 20 Percent Shipping Toll
Trump announced his plan during a morning phone interview on "Fox & Friends" before spelling out the details on social media.
"We’re going to keep the strait, and we’ll probably run it," Trump told the program. "We’ll become the guardian of the strait. Maybe we’ll call it the guardian angel of the strait. And we should be reimbursed for that."
The proposed 20% toll is meant to cover "any and all costs" of deploying the U.S. Navy to secure the passage. It sounds straightforward on television. In practice, it is incredibly messy.
First, consider the sheer scale of the transit. We are talking about billions of dollars in cargo daily. If the U.S. imposes a 20% levy on oil shipments, it adds an immediate, massive tax on global energy. On a standard shipment of crude oil, a 20% fee would add roughly $16 per barrel to the cost of Brent crude, which is already hovering around $80.
Who actually pays that bill? It won't be Iran. It will be the global consumers, particularly in Asia and Europe, who rely on Middle Eastern oil.
Legal Grounding and the UN Pushback
The reaction from international bodies was swift and highly critical. The United Nations' International Maritime Organization (IMO) wasted no time in pushing back against the announcement.
The IMO stated flatly that there is absolutely no legal basis for any nation to unilaterally impose tolls on an international strait. Under the 1982 United Nations Convention on the Law of the Sea (UNCLOS), the Strait of Hormuz is recognized as an international waterway. This designation guarantees the right of "transit passage" for all vessels. This means ships have the right to continuous and expeditious navigation without interference, fees, or political blockades.
Even though the U.S. has never formally ratified UNCLOS, it has historically treated its transit provisions as customary international law. By attempting to collect a fee, the Trump administration is effectively trying to rewrite decades of global maritime rules.
Industry experts and legal scholars are already warning that shipping companies will resist. If a commercial ship refuses to pay the 20% toll, what does the U.S. Navy do? Does it seize the ship? Does it deny entry? Treating allied commercial vessels like toll evaders would quickly alienate the very partners the U.S. claims to protect.
What This Means for Global Oil Prices and Supply Chains
Energy markets reacted instantly to the news. Oil prices jumped more than 5% on Monday, bringing Brent crude back up to the $80-a-barrel mark.
Markets hate uncertainty. For the past several months, oil prices had actually started to settle down to pre-war levels as negotiators attempted to work out a ceasefire. That progress is now completely erased.
For international shippers, this is a worst-case scenario. Insurance premiums for vessels traveling through the Persian Gulf were already astronomical. If you add a mandatory 20% U.S. security fee on top of skyrocketing war-risk insurance, sailing through the Persian Gulf becomes financially ruinous for many operators.
Some shipping giants might decide to bypass the Middle East altogether where possible, though that is physically impossible for oil coming out of Kuwait, Iraq, and the United Arab Emirates. Those nations are entirely dependent on the Strait of Hormuz to get their product to market. They now find themselves caught in a vice between Iranian threats and American financial demands.
The Tactical Reality on the Water
To understand how we got here, we have to look at what has been happening on the water over the last few weeks. The U.S. and Iran have been trading blows in an escalating maritime conflict.
Iran recently claimed to have closed the waterway entirely, establishing what it called a "Strait Authority." This move followed a series of U.S. airstrikes against Iranian-backed targets. Tehran claimed it was halting shipping to restore "stability and calm" after what it called unauthorized transits by Western vessels along the coast of Oman.
Trump’s blockade announcement is a direct counter to that Iranian claim. The administration wants to prove that the U.S., not Iran, dictates who moves through the region.
But a naval blockade is a highly aggressive act of war. Reinstating a true blockade means American warships must physically intercept, board, and inspect vessels suspected of trading with Iran. It is highly resource-intensive. Doing this while simultaneously trying to run a toll booth for all other commercial traffic is a logistical nightmare.
The U.S. military is already stretched thin. Securing the strait requires constant aerial surveillance, minesweeping capabilities, and destroyer escorts. Operating this security umbrella is incredibly expensive, which is precisely why Trump wants other nations to foot the bill. But turning the U.S. Navy into a commercial security force paid for by international shipping lines is a precedent most maritime nations are desperate to avoid.
The Road Ahead for International Shippers
So, what should shipping companies and energy buyers do right now?
First, prepare for extreme price volatility. Do not expect oil prices to stabilize anytime soon. The conflict between Washington and Tehran is entering a much more unpredictable phase where economic warfare and physical military actions are deeply intertwined.
Second, expect legal challenges. Shipping registries in nations like Panama, Liberia, and the Marshall Islands are highly likely to challenge any U.S. effort to collect fees under international maritime law. If you operate vessels in this region, consult your legal teams immediately regarding the enforceability of these proposed fees.
Finally, keep a close eye on allied responses. Leaders from the G7, including British Prime Minister Sir Keir Starmer, have recently reconfirmed their commitment to free transit passage without tolls. If the U.S. pushes forward with this plan, it could create a massive diplomatic rift with its closest European and Asian allies. The coming weeks will reveal whether this is a hardline negotiating tactic or a literal policy the White House intends to enforce with naval guns.
