Within a 48-hour window ending May 11, the United States publicly disclosed the arrival of a nuclear ballistic missile submarine at Gibraltar, Iran’s Navy commander officially confirmed Ghadir-class midget submarine deployments inside the Strait of Hormuz, and the ceasefire framework between Washington and Tehran publicly collapsed. These three events are not coincidental. They represent a coordinated, if fragile, exchange of deterrence signals between two parties that have lost the surface war and are now contesting the underwater domain.

As of Monday, the United States announced it would begin guiding ships through the Strait of Hormuz with the support of guided-missile destroyers, more than 100 aircraft, and 15,000 service members. A tanker was struck by unknown projectiles in the strait within hours of the announcement. The dual blockade — the U.S. Navy preventing access to Iranian ports while Iran restricts commercial shipping through the strait — has now entered a phase where each side is testing the other’s escalation threshold in a waterway that carries roughly one-fifth of daily global oil production.

A guided-missile destroyer has turned back the tenth vessel attempting to evade the U.S. naval blockade of Iran, as the interdiction operation enters its fourth day with an unbroken record.

The USS Spruance (DDG 111) intercepted an Iranian-flagged cargo ship that had departed Bandar Abbas, cleared the Strait of Hormuz, and was transiting westward along the Iranian coastline in an apparent attempt to circumvent the cordon. The Spruance successfully redirected the vessel, which is now returning to Iran.