Praise new or old country (6)
I believe the answer is:
persia
'old country' is the definition.
(historical term for Iran)
'praise new' is the wordplay.
'new' indicates anagramming the letters.
'praise' with letters rearranged gives 'PERSIA'.
'or' is the link.
(Other definitions for persia that I've seen before include "Praise be to ancient Iran" , "It's now known as Iran" , "Aspire to this old country" , "Former name of Iran" , "Old name for country at 25 Across" .)