Iran has intensified naval operations in the Persian Gulf, unveiling advanced unmanned underwater vehicles that extend its fight from the shoreline down to the seabed and directly threaten U.S. forces in and around the Strait of Hormuz, the narrow corridor that carries nearly 20% of the world’s oil. Branded by analysts as low‑cost “invisible killer” drones, these Nazir‑series UUVs can loiter silently for up to 24 hours at depths of around 200 meters, exploit shallow, acoustically complex Gulf waters, and combine mine‑warfare and torpedo‑attack roles that complicate U.S. maritime domain awareness and burden American carrier strike group sensors in an already constrained battlespace.