This dissertation is an ethnography of development and affliction among Lisu subsistence farmers in the Nu River Valley on the China-Myanmar border. The Lisu are a transnational ethnic community living across the highlands of mainland Southeast Asia, a region referred to by some scholars as “Zomia.” State-led development in this borderland region has lifted many thousands of Lisu out of absolute poverty. But many Lisu communities continue to struggle with high rates of violence, alcoholism, disease, and mental illness, which they often understand in terms of traditional afflictions such as haunting (ni lele), curses (ju), and demon madness (ni mei). Why do the Lisu, like indigenous and minority communities in other places, continue to suffer from such afflictions despite great economic improvements? Building on a decade of engagement and two years of continuous fieldwork with Lisu subsistence farmers, this dissertation analyzes afflictions as speech acts with political effects. I argue that Lisu afflictions are not merely symptoms of vulnerability but also articulate colonial and violent dimensions of development, such as cultural hierarchies that rank people from primitive to modern.