The quantum computing revolution will render all current public-key cryptography obsolete, exposing financial systems, digital identities, and critical infrastructure to catastrophic attack. This book presents a comprehensive framework for post-quantum governance, arguing that the quantum transition is not merely a technical migration but a profound governance crisis requiring institutional transformation, strategic foresight, and international cooperation. It analyzes asymmetric exposure of emerging economies, develops crypto-agility as the architecture of resilience, and presents strategies for building quantum-ready organizations and nations. Drawing lessons from the nuclear arms race and grounded in ethical principles of human dignity, privacy, security, justice, accountability, and participation, the book offers a vision of the post-quantum world and a call to action for governments, corporations, scientists, and citizens. The window for proactive migration is closing. The time to act is now.