Bankers destabilised a US state (8)
I believe the answer is:
nebraska
'us state' is the definition.
(I've seen this before)
'bankers destabilised a' is the wordplay.
'destabilised' is an anagram indicator (the order of letters is destabilised).
'bankers' with letters rearranged gives 'nebrask'.
'nebrask'+'a'='NEBRASKA'
(Other definitions for nebraska that I've seen before include "Cornhusker State" , "State of central US" , "Midwest state - Springsteen album" , "US Great Plains state" , "State N. of Kansas" .)