Steps taken to deceive left-wing extremist (7)
I believe the answer is:
'steps taken' is the definition.
'deceive left-wing extremist' is the wordplay.
'deceive' becomes 'fox' (foxing is a kind of deceiving).
'left-wing extremist' becomes 'trot' (short for Trotskyist).
'to' is the link.
(Other definitions for foxtrot that I've seen before include "Ballroom dance in quadruple time" , "Lively ballroom dance" .)