This book examines how the Taliban were able to regain power in Afghanistan in 2021, some 20 years after the US intervention.The volume presents an analysis of the factors that contributed to the Taliban’s ability to seize power following the withdrawal of the international coalition in August 2021, marking the end of 20 years of international engagement in the country. It is the result of a thorough review of research and policy publications over the course of 20 years, and is bas...