Ruling country's in talks (5)
I believe the answer is:
ukase
'ruling' is the definition.
(thesaurus)
'country's in talks' is the wordplay.
'country' becomes 'UK' (UK is an example).
'in talks' becomes 'ase' (I am not sure about this - if you are sure you should believe this answer much more).
'uk'+'ase'='UKASE'
Can you help me to learn more?
(Other definitions for ukase that I've seen before include "Old Russian edict" , "Decree or edict from Russia" , "Formerly, edict of the Russian tsar" , "Legal order" , "Official or arbitrary decree" .)