Allied nations (4)
I believe the answer is:
bloc
'allied nations' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bloc that I've seen before include "A number of countries" , "Group of allied nations" , "Group acting together" , "Group of parties or countries united in common interest - sounds wooden" , "Combination of parties or countries" .)