Yemen's Houthi forces declared the Bab al-Mandab Strait shut to Saudi shipping on Monday 20 July, using open radio warnings alone. Six vessels, among them the Chinese tanker Xin Long Yang, changed course inside 48 hours with no boarding, missile or shot fired.
Operation Aspides, the EU's Red Sea protection mission, still rates the threat as live. Roughly a quarter of world container traffic passes this strait, so a radio warning now diverts tankers as effectively as gunfire once did.
