Why does C++ not allow inherited friendship?

Question

Why is friendship not at least optionally inheritable in C++? I understand transitivity and reflexivity being forbidden for obvious reasons (I say this only to head off sim

Answer 1

C++ Standard, section 11.4/8

Friendship is neither inherited nor transitive.

If friendship would be inherited, then a class that wasn't meant to be a friend would suddenly have access to your class internals and that violates encapsulation.