Sovereign compute is rented: no legal guarantee of access to US-controlled infrastructure on UK soil

Public compute (AIRR, ~21 ExaFLOPs) is dwarfed by the hyperscaler build-out under the September 2025 Tech Prosperity Deal (~£31bn: Microsoft £22bn, Stargate UK via Nscale/OpenAI/NVIDIA in the North East AI Growth Zone). These assets sit on UK soil but under US corporate control and US export-control/executive-order jurisdiction. The CMA's cloud market investigation (July 2025) found AWS and Microsoft each hold 30-40% of UK cloud and recommended Strategic Market Status designation, but the CMA Board declined to prioritise the SMS investigations. No contract or statute guarantees UK access in a rationing scenario like Europe-2031's FISR tiers, where UK Tier-1 status is discretionary.

The UK's AI strategy assumes continuous access to US models and compute. That access is a policy choice made in Washington, revocable without notice. Physical location of data centres confers no sovereignty unless anchored in law: the central lesson of the Europe-2031 scenario.

Legal anchoring written into AI Growth Zone planning and power deals: statutory step-in/priority-access rights for designated critical workloads, escrow arrangements for weights/data serving UK public services, a government compute reserve for continuity, plus reviving the shelved SMS designations of AWS and Microsoft.

// State-led: Instrument: statutory step-in/priority-access rights, escrow mandates and revived SMS designations.

£31bn of US-controlled compute is being contracted onto UK soil right now with no legal access guarantee; step-in rights cannot be retrofitted once the deals close.