Volume III: Quantum Memory, Dual Clocks and Sovereign Readiness: Architectural Integration, Cost-of-Delay Prioritisation and Policy Implications

This third volume in the series examines the practical integration of quantum memory specifications with modular cryogenic architectures and the dual-clock framework of quantum readiness. Building on the hardware metrics and narrative trends established earlier, it develops a structured account of how memory elements, high-rate interconnects and crypto-agility interact under realistic lead-time constraints. Particular attention is given to cost-of-delay models that place classical residual risk and irreversible harvest-now-decrypt-later exposure on a common currency-per-year scale, thereby supplying an ordered prioritisation for migration sequencing. The analysis extends to sovereign and Global South contexts, where early investment in inventory capability, open standards and selective modular participation can reduce dependency risk even while full fault-tolerant machines remain on provisional roadmaps. The volume concludes that architectural and governance decisions taken in the current window dominate exposure outcomes more than any single predicted date for a cryptographically relevant quantum computer.