Damaged elastic wears thin (2,3,4)
I believe the answer is:
in the wars
'damaged' is the definition.
(something that's been 'in the wars' is damaged)
'elastic wears thin' is the wordplay.
'elastic' indicates an anagram (the anagram stretches or twists into a new form).
'wears'+'thin'='wearsthin'
'wearsthin' with letters rearranged gives 'IN THE WARS'.
(Other definitions for in the wars that I've seen before include "Knocked around" , "Hurt or knocked about" , "suffering" .)