Old German chancellor perhaps unaffected by revolution (4)
I believe the answer is:
otto
'old german' is the definition.
'otto' can be an answer for 'german' (common German name). I am unsure of the 'old' bit.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for otto that I've seen before include "Reversible German" , "Emperor's" , "Palindromic German boy's name" , "- - Preminger (films)" , "Possibly a German" .)