What makes one blush, showing some change of heart? Behaving badly (5)
I believe the answer is:
rogue
'behaving badly' is the definition.
(as in a rogue state, a nation behaving badly)
I don't understand how the remainder of the clue works.
(Other definitions for rogue that I've seen before include "Prankster" , "Deceitful and unreliable scoundrel" , "A dishonest or unprincipled person" , "Scoundrel, knave" , "Rascal or reprobate" .)