Communism is basically this: >>13656922
How do you conquer gentiles?
Overthrow their current authority.
How?
Whip up the poor, the disinherited, the idealistic young (who don't have much saved up yet), the junkies, the outcasts, etc, and trick them into risking life and limb for regime change.
Promise them enough for everybody to eat, when in power you can systematically starve targeted populations. Why don't they overthrow you? Because after the revolution, the revolutionaries are the first purged.