Recognise why attack's mounted after head of state loses face (8)
I believe the answer is:
'recognise' is the definition.
(to recognise someone or something)
I don't understand how the remainder of the clue works.
(Other definitions for identify that I've seen before include "Diagnose" , "Pick out" , "Recognise, put name to" , "Sympathise" , "Pinpoint" .)