Conscious of a conflict ending in peace (5)
I believe the answer is:
aware
'conscious of' is the definition.
(being conscious means being aware of something)
'a conflict ending in peace' is the wordplay.
'conflict' becomes 'war' (war is a kind of conflict).
'ending in' suggests the final letters.
The last letter of 'peace' is 'e'.
'a'+'war'+'e'='AWARE'
(Other definitions for aware that I've seen before include "Bearing in mind" , "Having knowledge (of fact)" , "Conscious, knowing about" , "Acquainted with or mindful of" , "Knowing (of something)" .)