Eastern European country is right to love madness (7)
I believe the answer is:
romania
'eastern european country' is the definition.
(I've seen this before)
'right to love madness' is the wordplay.
'right' becomes 'r' (common abbreviation).
'to love' becomes 'o' (love means zero in tennis).
'madness' becomes 'mania' (I've seen this before).
'r'+'o'+'mania'='ROMANIA'
'is' acts as a link.
(Other definitions for romania that I've seen before include "Oman air in the eastern European state" , "Country in SE Europe" , "Balkan country" , "Bucharest is its capital" , "East European country" .)