Their website states:
As a result of current world events, the Barksdale Global Power Museum is performing the following safeguards for our visitors:
•A Government issued ID, (Drivers License, Passport etc.) is required to gain entry at the gate entrance.
•All vehicles are subject to search.
•No backpacks, briefcases or large bags will be allowed in any buildings.
•Visitors please sign in upon entering the museum.
Nowhere does it state that non-US personnel aren't welcome....