Well the Holocaust certainly is one of many examples in human history that often times the rarest commodity is the volition to act (violently), and really understanding when you have nothing to lose.
Although its really tough to do.
Most people, they realize they ought to be killing the other guys, when their wife is being raped, or their half-starved already, and they seee the barbed-wire fences for the first time. It either takes an extreme effort of mental will power from the logical side to start comitting mayhem in your own neighborhood, or you have to access your "criminal side", if you have one.
Unless you're a child, or severely disabled, as long as you act while you still have the latitude to do so, and you give it a bit of thought, you should be able to get at least one, even if all you have is a rope or a table-leg, before you go down yourself.
And it's horrible, but reprisals against family, or the entire community are never done unless you're all considered disposable already anyway.