How sea mines threaten global trade, and how navies detect them

U.S. intelligence officials have assessed that Iranian forces deployed a small number of mines in the Strait of Hormuz, a critical global shipping chokepoint, according to reports. Modern sea mines use multiple sensing modes—including magnetic, acoustic, and pressure signatures—and some are designed to detonate only after a certain number of ships pass, allowing them to ignore minesweeping attempts. The U.S. Navy recently decommissioned its minesweeping vessels in the Persian Gulf but retains other ships and aircraft capable of finding and destroying mines. Mine detection relies on a "detect-classify-identify pipeline" using sonar deployed from uncrewed vehicles, with divers or cameras providing final confirmation. The British Royal Navy is also preparing to send towed sonar arrays to the Persian Gulf region.