The second edition of Seapower: A Guide for the Twenty-First Century by Geoffrey Till is a seminal work offering a comprehensive guide to naval power and maritime strategy in the 21st century. This book underscores the continued centrality of the sea as a source of resources, transportation, and strategic dominance, essential for global prosperity and security. In an increasingly globalized world, Till examines how navies and other forms of maritime power must adapt to fulfill traditional roles while also addressing emerging responsibilities. This updated edition builds on its predecessor, making it an indispensable resource for students of naval history and maritime strategy, as well as anyone interested in the evolving role of seapower.