Childhoods End Chapter 2

Fifty years is ample time in which to change a world beyond recognition and its people almost beyond recognition. The only things required for the task are a sound knowledge of social engineering, a clear sight of the intended goal and power.
These things the Overlords possessed. Though their goal was hidden, their knowledge was obvious and so was their power.
That power took many forms, few of them realized by the peoples whose destinies the Overlords now ruled. The might enshrined in their great ships had been clear enough for every eye to see. But behind that display of sleeping force were other and much subtler weapons.