Reply #1: An invitation is not a job or an obligation

[Spinzonner]

it's an opportunity.

If he doesn't feel it's his role or isn't comfortable doing it, he doesn't need to and shouldn't be expected to by anyone.

Teachers can only (largely) speak to the curriculum and that is subject to all kinds of political pressures and highly sanitized.

Veterans who were there can speak to the realities of war itself and not the idealistic and abstract things to be usually found in the textbooks and associated lectures.