Power bloc
From Tardis Wiki, the free Doctor Who reference
The Fifth Doctor knew that, in Tegan Jovanka's time, Earth had two power blocs, a state of affairs which continued to as late as 2084. By that point, the opposing power blocs were designated the West Bloc and the East Bloc. (TV: Warriors of the Deep [+]Loading...["Warriors of the Deep (TV story)"], PROSE: Warriors of the Deep [+]Loading...["Warriors of the Deep (novelisation)"])