Principle unaffected by revolution (5)
I believe the answer is:
tenet
'principle' is the definition.
(a tenet is a principle or value)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for tenet that I've seen before include "Item of belief" , "A religious doctrine proclaimed as true without proof" , "Key principle" , "A palindromic doctrine or belief" , "Palindromic principle or belief" .)