Feel restricting American power creates tension (8)
I believe the answer is:
suspense
'tension' is the definition.
(thesaurus)
'feel restricting american power' is the wordplay.
'feel' becomes 'sense' ('sense' can be a synonym of 'feel'**).
'restricting' means one lot of letters goes inside another.
'american' becomes 'us'.
'power' becomes 'p'.
'us'+'p'='usp'
'sense' enclosing 'usp' is 'SUSPENSE'.
'creates' acts as a link.
(Other definitions for suspense that I've seen before include "Alfred Hitchcock was the master of it" , "Nervous anticipation" , "Nervous uncertainty; cessation" , "expectancy" , "State of uncertainty or excitement" .)