Country militia had to show up (5)
I believe the answer is:
haiti
'country' is the definition.
(Haiti is an example)
'militia had to show up' is the wordplay.
'to show' indicates a hidden word.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'itiah' is hidden in the letters of 'militia had'.
'itiah' back-to-front is 'HAITI'.
(Other definitions for haiti that I've seen before include "West part of Hispaniola" , "Western part of island discovered by Columbus in 1492" , "W. Indies republic on Hispaniola" , "earthquake-hit area" , "Caribbean republic" .)