Bond has Interpol worried about one (12)
I believe the answer is:
relationship
'bond' is the definition.
(I have seen 'Emotional bond ' mean 'relationship' so perhaps 'bond' could also mean 'relationship')
'has interpol worried about one' is the wordplay.
'worried' indicates an anagram (worry can mean to interfere with or disturb).
'about' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'has'+'interpol'='hasinterpol'
'hasinterpol' anagrammed gives 'relationshp'.
'relationshp' enclosing 'i' is 'RELATIONSHIP'.
(Other definitions for relationship that I've seen before include "Emotional bond" , "Linkage; affair" , "Association, connection" , "Intimate affair" , "Connection, bond" .)