Nigeria, Sept. 27 -- On 7 June, this column unveiled the Decoupling Sovereignty Index (DSI) as the quantitative extension of the Trinity of Sovereignty Decay (TSD) theory, formerly known as the Trinity of State Decay. It is a measurement instrument designed to track the degree to which a state's formal authority has separated from its practical, lived reality on the ground. But the index measures a condition with a human face - and that face belongs to a peculiar kind of disappearance: one that does not require a person to die.

A person can remain alive, remain within the borders of a country, retain a name, a nationality and perhaps even a national identity document, and yet become progressively invisible to the institutions that are su...