Muhammad Ali al-Houthi, a senior leader in the Yemen’s Iran-backed Houthi movement, has advised Saudi Arabia to respond firmly to US threats following OPEC’s recent decision to cut oil production. The Houthi movement, which seized control of the Yemeni capital Sana’a in 2014, has been at war with Saudi Arabia for over seven years. In a tweet, the former president of the Houthi group’s Supreme Revolutionary Committee said the more pressure the US exerts on Saudi Arabia, the more the Saudis must exert pressure on OPEC+ to reduce oil production. He added a hashtag saying the United Nations Securi…