Blockade 101: American sea power on display as Trump corners Iran and warns off China

China imports about 11M barrels of oil per day, with 90% moving by sea routes the US Navy now controls

By Rebecca Grant

Published April 15, 2026 5:00am EDT | Updated April 15, 2026 5:40am EDT

At this moment in time, President Donald Trump has control of the Strait of Hormuz. His short-term goal, of course, is to pressure Iran’s leaders to give up their nuclear ambitions. Yet Trump’s blockade is also a major geopolitical hammer on China. For now, oil and petrochemical shipments will flow out of that waterway only under the rules of the U.S. Navy. All China can do is watch.

"If any of these ships come anywhere close to our BLOCKADE, they will be immediately ELIMINATED, using the same system of kill that we use against the drug dealers on boats at Sea," Trump wrote. "It is quick and brutal."

Admiral Brad Cooper, Commander, United States Central Command, has come up with a brilliant plan to pin down Iran while leaving Gulf states free to resume shipping. "The blockade will be enforced impartially against vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman," U.S. Central Command said.

Here’s how it works. Are you a legit VLCC (Very Large Crude Carrier) supertanker coming out of port in the UAE or Saudi Arabia, for example? U.S. Central Command says you are good to go. Remember to contact and monitor naval forces on VHF Channel 16 for bridge-to-bridge communications.

On the other hand, if you are a ship that picked up a cargo in Iran, you are in big trouble. Aircraft and ships of U.S. Central Command have vessels under constant surveillance. Yes, it’s the same clear view seen with the drug boat strikes in the Caribbean. Military maritime moving target indicator systems even have the ability to "rewind" and track ships from where they left port. Don’t forget ships violating the rules can be intercepted in deep water, too. There’s a lot of U.S. Navy in the North Arabian Gulf.

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At this point, there is little Iran can do to overturn Trump’s blockade. Airstrikes have cratered underground anti-ship cruise missile bunkers. The IRGC fast boats will be on a suicide mission if they attempt hit-and-run attacks. Drone defenses are in place. U.S. aircraft are active during the ceasefire and can respond fast if Iran strikes out.

Trump’s blockade of Iranian ports is a testament to American air and maritime dominance. It’s also a vivid reminder to Xi Jinping of China’s vulnerability. China imports about 11 million barrels of oil per day, and 90% of it moves by sea. Trump’s desired end-state is freedom of navigation in the Strait of Hormuz, but meanwhile, Trump is showing China that the U.S. Navy can control its single most important oil route at will. That’s a real blow against the China-Russia cabal.