Yemen's Iranian-backed Houthi rebels have announced a maritime embargo against Saudi Arabia. Monday's decision comes in retaliation for a blockade on Yemen and a recent attack on Sanaa International Airport. The embargo affects the Bab al-Mandeb strait, a crucial waterway for global trade and gateway to the Red Sea as Saudi Arabia seeks an alternative to the Iran-gripped Strait of Hormuz. The blockade raises fears of renewed conflict in the region. Saudi Arabia has not responded. The situation threatens to disrupt global shipping routes and increase costs. The Houthis demonstrated their ability to disrupt shipping there during the war in Gaza.