The U.S. is warning of possible rapid escalation across the Middle East as tensions rise around Iran, Yemen and Saudi Arabia. An advisory from the U.S. Embassy in the UAE cautions Americans about potential flight cancellations, airspace closures and possible retaliation by Iran and its regional allies, including the Houthis. The warning comes amid reports of renewed Saudi-Emirati military action in Yemen, fuelling concerns that the confrontation could spread and threaten regional security.