Nation raising tax on 50 per cent of realty (7)
I believe the answer is:
eritrea
'nation' is the definition.
(I've seen this before)
'raising tax on 50 per cent of realty' is the wordplay.
'raising' says the letters should be written backwards (in a down clue, letters go up).
'tax' becomes 'tire' (I've seen this in another clue).
'on' says to put letters next to each other.
'50 per cent of' indicates taking half.
'tire' back-to-front is 'erit'.
'realty' with half the letters taken is 'rea'.
'erit'+'rea'='ERITREA'
(Other definitions for eritrea that I've seen before include "Province of Ethiopia on the Red Sea" , "NE African state" , "It declared its independence from Ethiopia in 1993" , "It became independent of Ethiopia in 1993" , "Country bordering the Red Sea" .)