Political alliance (9)
(Other definitions for alignment that I've seen before include "in a row?" , "Political side taken" , "union" , "Conformity - straightening" , "Order" .)
'political alliance' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for bloc that I've seen before include "Political grouping of countries" , "multinational group" , "Political coalition" , "League" , "Political group of nations" .)