Iran’s Revolutionary Guard has announced that the Strait of Hormuz is closed to all vessels and warned ships not to approach because their security could be at risk.
BREAKING: Iran's IRGC has officially declared the Strait of Hormuz closed to all vessels in response to the US violation of the Memorandum of Understanding first clause and Israel's continuous violations of the Lebanon ceasefire, per Tasnim.
Iran says this is the "first step"…
— The Hormuz Letter (@HormuzLetter) June 20, 2026
The reason given is a dispute over the recent memorandum of understanding, with Iran accusing the U.S. of violating the deal and demanding that Israel stop actions in Lebanon.
At the same time, Iran’s diplomatic side is saying something different.
Iran’s Foreign Ministry says it followed the agreement and plans to send a delegation to Switzerland to push the other side to honor its commitments.
That is the part that makes this situation complicated.
The military message is escalation.
The diplomatic message is negotiation.
And markets are left trying to figure out which one matters more.
The Strait of Hormuz is not just another shipping route. A large share of the world’s oil passes through that narrow waterway, which means any real disruption could send oil prices higher quickly.
The big question is whether this is a real attempt to block shipping or another pressure tactic from Iran.
Iran has a long history of using aggressive language while stopping short of completely shutting down the route.
But shipping companies do not need a full closure to react.
If vessels start avoiding the area because of security concerns, insurance costs rise, routes change, and energy markets can move before any official blockade happens.
Right now the biggest thing to watch is not just what Iran says.
It is what ships actually do.
IRAN'S IRGC WARNS VESSELS NOT TO APPROACH STRAIT OF HORMUZ, SAYS THEIR SECURITY WOULD OTHERWISE BE AT RISK -STATEMENT
— *Walter Bloomberg (@DeItaone) June 20, 2026