After a long period of passively absorbing blows by Iranian proxies from Baghdad to Bab-el-Mandeb, the United States is striking back against Houthis and Iraqi militias alike. But with American casualties in the Red Sea and Jordan, there is a growing risk of further escalation, with the U.S. running head-on into Iran’s ambitious regional aspirations for dominance. What are the prospects for either a conflagration or a cooling down?