Nigeria, April 19 -- A nation does not collapse all at once. It erodes - layer by layer, system by system - until what once appeared unshakable begins to give way under the weight of forces it can no longer contain.

This column said that last week. It bears repeating now because there are moments in the life of a crisis when description is no longer enough - when the accumulation of evidence: the kidnapped schoolgirls, the abandoned farms, the bombed houses of worship, the ransomed businessmen, the burning villages, demands not another account of what is happening, but a coherent theory of why it is happening, how the pieces connect, and what it means.

We have arrived at that moment.

In The Sunday Stew, this inquiry has already traced ...