I found this:
Army Regulation 165-1, 12-3k:”The chapel environment will be religiously neutral when the facility is not being used for scheduled worship. Portable religious symbols, icons, or statues may be used within a chapel during times of religious worship.”
“Symbols are to be moved or covered when not in use during services. Distinctive religious symbols, such as crosses, crucifixes, the Star of David, Menorah, and other religious symbols will not be affixed or displayed permanently on the chapel interior, exterior, or grounds. Permanent or fixed chapel furnishings, such as the altar, pulpit, lectern, or communion rail will be devoid of distinctive religious symbols.”
Which I think is SUPER fair. Everybody has a "safe" space to go to so that they may practice their chosen religion in peace without being bombarded by all the other religious iconography. They put up the stuff they want when they use the space and the next guy does the same thing.