To break the back of a people, make them watch as you destroy their children — ever so slowly.
Miseducate them. Undereducate them. Cause them to crave that which will kill them… the slower, the better.
And the old are undermined by the destruction of the young, because the young contain the spirit of the times — they define the moment. Having poured their vital energies into the young through nurturance, as the old move into natural decline, they depend upon the appreciation and return of their gifted energy for their very lives. When the young are stymied, no such appreciation of energies will occur.