This book is a comprehensive guide for foreign policy practitioners navigating the transformative impact of AI on diplomacy and statecraft. It begins by simplifying AI technologies for non-technical readers and tracing historical parallels of how these transformative technologies have reshaped diplomacy. Organized into three themes - Progress, Power, and Peace - it explores AI as a frontier reshaping international affairs. The Progress and Power sections examine AI's role in geopolitical competition, economic security, and the rise of Big Tech as quasi-sovereign actors, alongside security threats like lethal autonomous systems and AI-driven cyber warfare. The Peace section offers practical insights, showcasing real-world AI applications in diplomacy, peacebuilding, and crisis management. The book also addresses ethical and governance challenges, such as algorithmic bias, the erosion of human control, and the race to regulate AI's rapid evolution. Concluding with aspirations rather than predictions, it envisions how nations can navigate AI rivalry, seize opportunities, and redirect technologies toward peace. Designed for flexibility, each chapter stands alone, enriched with quotes, case studies, and reflections to inspire readers to explore AI's implications for global diplomacy. This is not a book about tomorrow; it's about preparing for tomorrow by understanding the choices made today. Whether you're a diplomat seeking to understand these tools, a technologist grasping the geopolitical implications of your work, a student preparing for international relations, or a citizen navigating a changing world, this book offers a vital resource, grounded in real-world examples, to guide future work in becoming more informed and responsible.