US Central Command made it official late Sunday night: the American military will begin a full blockade of all Iranian ports on Monday, April 13th, at 10 a.m. Eastern Time. Every vessel entering or exiting Iranian waters will be stopped. The blockade will be "enforced impartially against vessels of all nations."

This is not a threat. This is not diplomatic posturing. This is a formal military announcement with a start time and a chain of command.

The timing matters. Marathon peace talks between the US and Iran in Islamabad collapsed after 21 hours of negotiations. Vice President JD Vance led the American delegation. Iran parliament speaker Mohammad Bagher Qalibaf led theirs. They could not agree on nuclear enrichment, the status of the Strait of Hormuz, or Israeli strikes on Lebanon. Within hours of the collapse, Trump went on Truth Social and ordered the Navy to "seek and interdict every vessel in International Waters that has paid a toll to Iran."

Iran Revolutionary Guard responded immediately: the strait remains under Iran full "control," and any military vessel attempting to enforce the blockade will receive a "forceful response." The IRGC issued what multiple outlets are calling a "deadly vortex" warning.

Why AI companies should be watching this closely

The Strait of Hormuz handled 20% of the world oil shipping before the war started. A military blockade targeting Iranian ports will not directly close the strait to non-Iranian traffic. CENTCOM explicitly said ships transiting between non-Iranian ports can still pass. But that distinction will not stop oil traders from panicking.

Brent crude futures are expected to gap up significantly when Asian markets open. Morgan Stanley analysts were already warning last week that AI energy demand is creating a structural electricity shortage. A blockade that sends oil prices spiraling adds a second layer of pain on top of an already strained grid.

Every major AI company is racing to build data centers that consume staggering amounts of electricity. OpenAI, Microsoft, Google, Meta, and Anthropic are collectively spending hundreds of billions on AI infrastructure. Much of that infrastructure runs on natural gas, and natural gas prices move with oil. A sustained blockade could add billions in annual operating costs to data centers that were already borderline uneconomic.

The ceasefire is dying

The two-week ceasefire between the US and Iran expires on April 22. Neither side indicated what happens after that. The talks collapsed over nuclear enrichment (the US demanded Iran give up enrichment entirely, Iran refused), control of the Strait of Hormuz (the US demanded unconditional reopening, Iran demanded sovereignty), and Lebanon (Israel killed over 350 people in Lebanon during the ceasefire, and Iran insisted the ceasefire must cover Lebanese territory too).

Former US Ambassador Nikki Haley called it "a game of chicken" on CNN. She is probably right. But games of chicken only work when both sides believe the other will swerve. The IRGC is not signaling that it plans to swerve.

What happens next

Monday morning will be the test. If the US Navy physically stops an Iranian-flagged vessel or a third-party tanker carrying Iranian oil, this becomes the most significant naval confrontation in the Middle East since the 1988 tanker war. If Iran retaliates, the ceasefire is over.

Three supertankers loaded with oil passed through the strait on Saturday, the first since the ceasefire began. That might be the last normal shipping day for a while.

For AI companies that have bet their futures on cheap, abundant electricity to power data centers: the cost of that bet just went up. Dramatically.