Result of European Union's almost fresh upset (5)
I believe the answer is:
ensue
'result' is the definition.
('ensue' can be a synonym of 'result')
'european union's almost fresh upset' is the wordplay.
'european union's' becomes 'eus'.
'almost' means to remove the last letter (most of the word but not all of it).
'fresh' becomes 'new' ('new' can be a synonym of 'fresh').
'upset' says the letters should be written backwards.
'new' with its last letter taken off is 'ne'.
'eus'+'ne'='eusne'
'eusne' back-to-front is 'ENSUE'.
'of' is the link.
(Other definitions for ensue that I've seen before include "Leading directly to" , "Happen as a result, follow ( 5)" , "Arise" , "Happen or come about as consequence" , "Turn out" .)