As Houthis attack Saudi Arabia, is Iran war escalating into regional conflict?

Saudi Arabia on Tuesday threatened to hit back after a wave of missiles from Yemen's Houthis set oil facilities ablaze and wounded dozens, the Iran-backed rebels' heaviest attack in years. It comes after a four-year truce collapsed in July, months into the Middle East war between the United States and Iran. France 24's Rochelle Ferguson Bouyahi provides analysis.