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 subsidiary indication.
'primarily' indicates taking the first letters.
'in' means one lot of letters goes inside another.
'volatile' indicates an anagram.
The first letter of 'leadership' is 'l'.
'tunis' is an anagram of 'insut'.
'l' going 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?".)