Force instrument on ex-vice president — no pressure! (8)
I believe the answer is:
violence
'force' is the definition.
(force can mean violence or aggression)
'instrument on ex-vice president no pressure' is the wordplay.
'instrument' becomes 'viol' (viol is a kind of instrument).
'on' means one lot of letters go next to another.
'ex-vice president' becomes 'Pence' (former US vice president Mike Pence).
'no' suggests deleting specific letters.
'pressure' becomes 'p' (abbreviation).
'pence' with 'p' removed is 'ence'.
'viol'+'ence'='VIOLENCE'
(Other definitions for violence that I've seen before include "Acts of aggression" , "Aggressive force" , "Use of great force or intensity" , "Ferocity" , "Destructive force" .)