Hierarchy
In dictatorship this is done by asking one powerful person to make the decision and then agreeing to force everyone to follow it. Any who will not are exiled, imprisoned, or killed, even if the decision is not very important, since the refusal to follow is taken as a challenge to the power structure itself. There is only one power network and all others are forced to become part of it, or fight it. Civil war is much more common in a dictatorship than in a democracy.