Al-Qaeda’s attack in Al-Mahfad, in southern Yemen, which killed nine Yemeni soldiers, underscores the fragility of the southern front and the extent to which external actors are now managing (not directing) Yemen’s war. AQAP (al-Qaeda in the Arabian Peninsula) is operating across the gaps between rival forces nominally under the Presidential Leadership Council, but practically loyal to separate sponsors. The STC dominates Aden and much of Lahj and Abyan with Emirati support. Islah-aligned units remain entrenched in Marib and parts of…