Deceptive tactic (4)
'deceptive tactic' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ruse that I've seen before include "Trick designed to deceive" , "Subterfuge" , "Cunning plan" , "Sure its a strange deception" , "Deceptive tactic" .)
(Other definitions for smokescreen that I've seen before include "Trick to disguise" , "Action intended to confuse or obscure" , "It conceals" , "Concealing suspension" , "Diversion" .)