Consequence of initiating kettling, as rioters may attack (5)
I believe the answer is:
karma
'consequence' is the definition.
(karma is cosmic consequence)
'initiating kettling as rioters may attack' is the wordplay.
'initiating' says to take the initial letters (I've seen 'initiated' mean this).
The first letters of 'kettling as rioters may attack' is 'KARMA'.
'of' acts as a link.
(Other definitions for karma that I've seen before include "Good or bad luck" , "Hindu destiny" , "In Buddhism, the sum of a person's existence - determines future" , "Retribution" , "Moral quality determining future life (Hinduism)" .)