Balkan citizen welcoming to American citizen (9)
I believe the answer is:
bostonian
'american citizen' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'balkan citizen welcoming to' is the wordplay.
'balkan citizen' becomes 'bosnian' (I can't explain this - if you can you should give a lot more credence to this answer).
'welcoming' means one lot of letters goes inside another (in sense of 'inviting in').
'bosnian' placed around 'to' is 'BOSTONIAN'.
Can you help me to learn more?
(Other definitions for bostonian that I've seen before include "US citizen" , "US state capitalist" .)