Justified tirade by journalist after conflict (9)
I believe the answer is:
warranted
'justified' is the definition.
('warrant' can be a synonym of 'justify')
'tirade by journalist after conflict' is the wordplay.
'tirade' becomes 'rant' (I've seen this before).
'by' says to put letters next to each other.
'journalist' becomes 'ed' (short for editor).
'after' means one lot of letters go next to another.
'conflict' becomes 'war' (war is a kind of conflict**).
'rant' put next to 'ed' is 'ranted'.
'ranted' put after 'war' is 'WARRANTED'.
(Another definition for warranted that I've seen is " Justified or guaranteed".)