Trump wants to impose fees for Strait of Hormuz transit just like Iran: Is that legal? - explainer

What Happened

US President Donald Trump declared on Monday that the United States would impose a 20 percent levy on all cargo transiting the Strait of Hormuz, asserting that the US would be 'THE GUARDIAN OF THE HORMUZ STRAIT' and would be reimbursed for its services. This follows the collapse of a ceasefire with Iran, which had shut the 21-mile-wide waterway on February 28 after the US and Israel attacked it. Trump’s social media post revived a June 20 threat, while Secretary of State Marco Rubio had told Gulf states on June 25 that no country has the right to charge for international waterways. Iran has made control over the strait its main negotiation priority and interprets an interim deal as granting it authority over safe passage without charge for only 60 days, while the US sees the language as merely requiring Iran to facilitate transit. On Tuesday, an Iranian National Security Commission member told Tasnim that Iran would resist external influence and never lose control of the strait. The article notes that neither Iran nor the US is party to UNCLOS, and that no modern precedent exists for a state unilaterally demanding passage fees through an international strait.

Key Actors

Why It Matters

The Strait of Hormuz is a maritime chokepoint for roughly one-fifth of global oil supplies and vital goods. A unilateral US toll or Iranian enforcement of its own control—including targeting vessels that do not comply—could disrupt international shipping, sharply raise energy prices, and provoke a military escalation. The dispute undermines norms of free navigation and UNCLOS, risks drawing in Gulf states and global consumers, and marks a dangerous turn in US-Iran relations following a collapsed ceasefire.

Watch For

Whether the US attempts to enforce the 20 percent fee and by what legal or military means; Iran's response, including potential attacks on ships avoiding its coordination; Oman's ongoing dialogue and any IMO reaction; formal protests from Gulf states and major trading nations; and further statements from Rubio or others clarifying the administration's stance. Also monitor whether Iran formalizes its own fee structure or expands control measures.