Power and honour in short supply ahead of conflict (3-3)

'ahead of conflict' is the definition.
(before a war)

'power and honour in short' is the wordplay.
'power' becomes 'p' (symbol in physics).
'and' means one lot of letters go next to another.
'honour' becomes 'reward' (synonyms).
'in short' means to remove the last letter.
'reward' with its final letter taken away is 'rewar'.
'p'+'rewar'='PRE-WAR'

'supply' is the link.