How old is footwear damage? (8)
I believe the answer is:
sabotage
'damage?' is the definition.
(I have seen 'Deliberate damage ' mean 'sabotage' so perhaps 'damage' could also mean 'sabotage')
I can't explain the rest of the clue.
(Other definitions for sabotage that I've seen before include "Treachery!" , "spoil things" , "Disrupt" , "Subvert" , "Vandalism" .)