The writer's upset with British stars in trade restriction (7)
I believe the answer is:
embargo
'trade restriction' is the definition.
'embargo' can be an answer for 'restriction' (thesaurus). I'm not certain of the 'trade' bit.
'the writer's upset with british stars' is the wordplay.
'the writer' becomes 'me' (the person who is writing these clues).
'upset' says the letters should be written backwards.
'with' is a charade indicator (letters next to each other).
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'stars' becomes 'argo' (I've seen this before).
'me' backwards is 'em'.
'em'+'b'+'argo'='EMBARGO'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for embargo that I've seen before include "Proscribe, ban" , "Ban; prohibition" , "Trade stoppage" , "Government trade ban" , "restrict trade" .)