In the two decades since the 9/11 attacks, terrorist networks have become more global and interconnected even as they remain locally tethered. The transnational and localized nature of the threat underscores the continued importance of international cooperation in all aspects of a response. This report explores the work of the Global Counterterrorism Forum, launched in 2011 to energize such cooperation, and how best to position it for an effective and far-reaching future.