Why do advocacy campaigns succeed in some cases but fail in others? What conditions motivate states to accept commitments championed by principled advocacy movements? Joshua Busby sheds light on these core questions through an investigation of four cases developing country debt relief, climate change, AIDS, and the International Criminal Court in the G-7 advanced industrialized countries (Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States). Drawing on hundreds of interviews with policy practitioners, he employs qualitative, comparative case study methods,...