Trouble dividing a mother and son upset spiritual leader (5,4)
I believe the answer is:
dalai lama
'spiritual leader' is the definition.
(Tibetan spiritual leader)
'trouble dividing a mother and son upset' is the wordplay.
'trouble' becomes 'ail' (synonyms).
'dividing' is an insertion indicator (inserted letters divide the word).
'mother' becomes 'ma' (ma can mean mother).
'and' says to put letters next to each other.
'son upset' becomes 'dal' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a'+'ma'='ama'
'ama' put after 'dal' is 'dalama'.
'ail' put into 'dalama' is 'DALAI LAMA'.
(Other definitions for dalai lama that I've seen before include "World's Buddhist leader, once ruler of Tibet" , "Tibetan religious leader" , "eastern leader" , "Tibetan Buddhist leader, meaning ocean monk" , "Tibetan exile" .)