National leader (7)
'national leader?' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for inter that I've seen before include "Prefix meaning in the middle" , "Entomb" , "Milan FC" , "Put under the earth" , "Settle in ground" .)
(Other definitions for premier that I've seen before include "Prime minister" , "Foremost" , "PM" , "Leading" , "First in rank or degree" .)