Flaw is found in disheartened team's intimidatory tactics (9)
I believe the answer is:
terrorism
'intimidatory tactics' is the definition.
(terrorism is designed to intimidate people)
'flaw is found in disheartened team's' is the wordplay.
'flaw' becomes 'error' (flaw can mean a mistake or imperfection).
'found in' indicates putting letters inside.
'disheartened' means to remove the middle letters.
'team' with its centre removed is 'tm'.
'error'+'is'='erroris'
'erroris' placed inside 'tm' is 'TERRORISM'.
(Other definitions for terrorism that I've seen before include "Unauthorised violence for political ends" , "Action of revolutionaries" .)