Offend leadership primarily in volatile Tunis (6)
I believe the answer is:
Here is my best explanation:
'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 "Demeaning remark", "Abuse (someone)", "Cause offence to", "Hurtful and offensive remark", "Slander", "Offensive remark", "Treat with contempt", "Speak or act inm abusive way", "Speak to or treat with disrespect" and "An addition to injury?".)