Smear nation state (6)
I believe the answer is:
Here is my best explanation:
'smear nation state' is the definition.
'grease' can be an answer for 'smear' (thesaurus). I am not sure about the 'nation state' bit.
'smear nation state' is the subsidiary indication.
'smear nation' becomes 'gr' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'state' becomes 'ease' (ease is a kind of state).
(Other definitions for grease that I've seen before include "-- gun; -- monkey", "Fully aware, astonished", "Musical starring John Travolta and Olivia Newton-John", "'Thick, fatty oil (6)'", "Lubricate - musical", "Film with Travolta and Newton-John", "Musical that sounds like a country", "Rock musical", "Oil" and "Fat, film".)