Capital of Iran changed by witchcraft? (7)
I believe the answer is:
nairobi
'capital' is the definition.
(Nairobi is an example)
'iran changed by witchcraft?' is the wordplay.
'changed' is an anagram indicator.
'by' means one lot of letters go next to another.
'witchcraft?' becomes 'obi' (I've seen this before).
'iran' is an anagram of 'nair'.
'nair'+'obi'='NAIROBI'
'of' is the link.
(Other definitions for nairobi that I've seen before include "The capital of Kenya (7)" , "East African capital" , "I, a robin (anag) - city" , "Badly-behaved child" , "African city" .)