Once known as the Janjaweed — a group of state-sponsored Arab militias that spearheaded the genocide in Darfur and traditionally operated near the Sudan-Chad border — the Rapid Support Forces (RSF) is dramatically expanding its geographic footprint. Under al-Bashir, the group was deployed to crush protests in Khartoum and to wage a brutal counterinsurgency in Sudan’s Nuba Mountains. The RSF is also increasingly doing the dirty work of foreign governments. Over the past five years, the group has deployed 40,000 fighters into Yemen and Libya to fight alongside forces loyal to the United Arab Emirates and Saudi Arabia. Some experts estimate that each fighter gets paid up to $10,000 a month — which amounts to a total annual wage bill of nearly $5 billion. Until recently, the RSF was patrolling Sudan’s borders as part of a European Union initiative — known as the Khartoum Process — to crack down on migration.