Suppose a workload runs in Frankfurt and its data stays there. Location alone does not tell you who can grant administrative access, unwrap a disk key, replace the software that runs the cloud, alter its audit trail or restore it when something fails.

Those are control plane questions. A cloud is sovereign only when its operator has the authority, keys, software and knowledge to keep it running without asking an outside party for permission. The operator must also be able to move or retire the platform without losing access to its data, configuration or control plane state.