Formerly having to make amends with the enemy (2,3,4)
I believe the answer is:
at one time
'formerly' is the definition.
(I've seen this before)
'to make amends with the enemy' is the wordplay.
'to make amends' becomes 'atone' (to atone is to make amends for a wrong deed).
'with' means one lot of letters go next to another.
'the enemy' becomes 'time' (the enemy when speaking figuratively).
'atone'+'time'='AT ONE TIME'
'having' is the link.
(Other definitions for at one time that I've seen before include "together" , "in former days" , "in concert" , "Taking place simultaneously" , "Formerly" .)