Country backing an American state (7)
I believe the answer is:
indiana
'american state' is the definition.
(I know that Indiana is a U.S. state)
'country backing an' is the wordplay.
'country' becomes 'India' (India is an example).
'backing' is a reversal indicator.
'an' back-to-front is 'na'.
'india'+'na'='INDIANA'
(Other definitions for indiana that I've seen before include "The Hoosier State" , "___ Jones (Raiders of the Lost Ark)" , "Part of US" , "State of central US" , "US Midwest state" .)