As leaders of law enforcement go in for peace (7)
I believe the answer is:
silence
'for peace' is the definition.
(I've seen this before)
'as leaders of law enforcement go in' is the wordplay.
'as' becomes 'since' (both can mean 'because').
'leaders of' indicates taking the first letters.
'go in' is an insertion indicator.
The initial letters of 'law enforcement' is 'le'.
'since' placed around 'le' is 'SILENCE'.
(Other definitions for silence that I've seen before include "Quietude" , "No talking" , "Period of peace" , "Secrecy; stillness" , "'The rest is - - '(Hamlet)" .)