Poles, worried, accept America's support (8)
I believe the answer is:
espousal
'support' is the definition.
(thesaurus)
'poles worried accept america's' is the wordplay.
'worried' indicates an anagram.
'accept' means one lot of letters goes inside another.
'america' becomes 'usa' ('U.S.A.' can be a synonym of 'america').
'poles' with letters rearranged gives 'espol'.
'espol' going around 'usa' is 'ESPOUSAL'.
(Other definitions for espousal that I've seen before include "Backing, support" , "Acceptance with approval" , "Adoption, support (of)" , "old-fashioned marriage" , "championship" .)