The recent attacks on Saudi oil facilities by Yemeni Houthi forces demonstrate once again that an aggressive foreign policy often brings unintended consequences and can result in blowback. In 2015 Saudi Arabia attacked its neighbor, Yemen, because a coup in that country ousted the Saudi-backed dictator. Four years later Yemen is in ruins, with nearly 100,000 Yemenis killed and millions more facing death by starvation. It has been rightly called the worst humanitarian catastrophe on the planet. But rich and powerful Saudi Arabia did not defeat Yemen. In fact, the Saudis last month asked the Trump Administration to help facilitate talks ...