Yemen is the most severe humanitarian crisis in the world today. Qatar, the UN, EU, US, and the Gulf Cooperation Council have tried to mediate the conflict between the Government of Yemen and the Houthis. But mediation efforts have been complicated by the duality of roles: some mediators have been directly involved as a conflict party, and others indirectly involved, providing support to those engaged in the war. These factors violate the mediation principle of impartiality and diminish a mediator’s credibility and leverage. In this brief, we analyze all mediation efforts between the Yemeni government and the Houthis since 2007, reviewing the strategies, outcomes, and implementation processes to identify the factors that have hindered successful mediation.