Notice the bloke's working to support international attachment (8)
I believe the answer is:
adhesion
'attachment' is the definition.
(I know that attachment can be written as adhesion)
'notice the bloke's working to support international' is the wordplay.
'notice' becomes 'ad' (short for advert).
'the bloke's' becomes 'hes' ('he' refers to a man).
'working' becomes 'on' (on can mean working or activated).
'to support' says to put letters next to each other (in a down clue, some letters hold up others).
'international' becomes 'i' (abbreviation eg in IMF).
'on' put after 'i' is 'ion'.
'ad'+'hes'+'ion'='ADHESION'
(Other definitions for adhesion that I've seen before include "Grip" , "The property of sticking" , "strong attachment" , "Stickiness" , "He's no aid to sticker" .)