Controversial European rationale (7)
I believe the answer is:
emotive
'controversial' is the definition.
(I've seen this before)
'european rationale' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'rationale' becomes 'motive' (I've seen this in another clue).
'e'+'motive'='EMOTIVE'
(Other definitions for emotive that I've seen before include "arousing passion" , "Arousing intense feeling" , "Sensitive - controversial" , "Showing feelings" , "Causing strong feelings" .)