It’s essential to defend soft goals (4)
I believe the answer is:
ends
'goals' is the definition.
(I know this)
'it's essential to defend soft' is the wordplay.
'it's essential to' indicates the answer is hidden within the clue (I've seen this in other clues).
'ENDS' is hidden in the letters of 'defend soft'.
(Other definitions for ends that I've seen before include "limits" , "Halts" , "passes away" , "They may justify the means" , "See 8" .)