Slip into the swirling mist of political violence (9)
I believe the answer is:
terrorism
'political violence' is the definition.
(I've seen this before)
'slip into the swirling mist' is the wordplay.
'slip' becomes 'error' (slip can mean an error or mistake).
'into' means one lot of letters goes inside another.
'the swirling' indicates anagramming the letters.
'mist' anagrammed gives 'tism'.
'error' put within 'tism' is 'TERRORISM'.
'of' is the link.
(Other definitions for terrorism that I've seen before include "Action of revolutionaries" , "Unauthorised violence for political ends" .)