American and Afghan officials are aiding anti-Taliban militias to start fighting against insurgents in Afghanistan. The emergence of anti-Taliban leaders has encouraged officials to help grow more like-minded armed groups across southern and eastern Afghanistan, where the Taliban has more control, with the hopes of starting a large-scale tribal rebellion against them. The goal is that the militias will quickly boost the number of Afghans fighting against the Taliban, which is especially important while the Afghan army and police forces are being trained. But Americans are trying to avoid repeating past mistakes: militias will stay connected to the Afghan government, will be limited to protecting villages and manning checkpoints, and will stay small. The plan is ambitious and risky because the militias could turn on one another, or against us. There's no need to arm the groups for now, because they already have guns.