any sign of the Yemeni tricolor. That flag — viewed by southerners as a vestige of northern oppression and now aggression — would indicate the government’s presence. In the absence of the state, there is often another banner in Yemen. Not for the first time, the black rayat al-uqab flag, embraced by Al-Qaeda and subsequently assumed by the Islamic State in Iraq and the Levant (ISIL), can be spotted on walls in districts across the city. When the combined forces of the predominantly northern Shia Houthis — along with loyalists of former President Ali Abdullah Saleh — descended on Aden in mid-March, their pretext for war was the city’s being a stronghold for Daesh (the Arabic acronym for ISIL). The Houthis and their supporters adopted the name asthe city. While the Southern Resistance busied itself with the military advance out of Aden into neighboring provinces last month, it appears the radical fighters were already thinking ahead and planning for the postconflict environment. During the last few weeks of battle, members of the Southern Resistance noticed a surge in presence of ISIL men who followed the push into Lahij and Abyan provinces but, they say, never took part in the fighting. Loitering at the rear, they swooped in as the fighting subsided to loot heavy weapons and ammunition left behind when the Houthis fled. “They knew exactly where to look,” noted one field commander who observed the tactic repeatedly. But in the increasingly gray area of who is and who is not AQAP or ISIL, trying