Why interview the Emperor when his reasoning seems known?

Is an interview with the Emperor useful if his reasoning is already known?

Yes, in the proposed exercise, direct questioning could test the perspective supplied by existing accounts.

An objection to interviewing the Emperor is that readers already have an account of his reasoning. Alex Clarke answers that this supplies a perspective, while a truthful interview would let him cross-examine it. The distinction is between accepting an existing narrative and asking questions designed to test what it leaves unexplained.