Offend leadership primarily in volatile Tunis (6)
I believe the answer is:
insult
'offend' is the definition.
(insulting is a kind of offending)
'leadership primarily in volatile tunis' is the wordplay.
'primarily' says to take the initial letters.
'in' is an insertion indicator.
'volatile' is an anagram indicator.
The first letter of 'leadership' is 'l'.
'tunis' anagrammed gives 'insut'.
'l' placed into 'insut' is 'INSULT'.
(Other definitions for insult that I've seen before include "Abuse (someone)" , "Speak to or treat with disrespect" , "Affront, offend" , "Show contempt to" , "Speak or act inm abusive way" .)