More vigilant - that is right after armed conflict (6)

'more vigilant' is the definition.
('wary' can be a synonym of 'vigilant')

'that is right after armed conflict' is the wordplay.
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'right' becomes 'r' (common abbreviation).
'after' says to put letters next to each other.
'armed conflict' becomes 'war' (I've seen this in another clue).
'ie'+'r'='ier'
'ier' put after 'war' is 'WARIER'.