Expaining The Holocaust & karma to a non-Buddhist How can you explain karma in the genocide of babies and "innocents" (For example: The Holocaust) in Buddhist terms to a non-Buddhist, without seeming cold and uncaring? Yesterday, I tried--by saying, "I cannot say unequivocally, why the millions had to suffer or whether karma came into play or not, but perhaps it is better to focus attention on the present and try to generate good karma here and now." I know Buddha said certain topics will only foster disputation and I felt like this is one of those that can only be speculation so I steered the conversation in another direction. What can you say in a better (or kinder) way to explain it to a non-Buddhist person who asks how the holocaust suffering can be justified and who expresses interest in knowing the Buddhist view about it?
The popular portrayal of kamma isn't what The Buddha believed in (if someone does good deeds then good things would happen to them or if they do evil deeds bad things will happen).

He thought that there were many different variables involved in one's experiences besides good or bad deeds.

There are also certain deeds perceived as good that are actually bad and other deeds perceived as bad that are actually good.

As explained in the Maha Kammavibhanga Sutta (MN 136) there are certain people who do evil deeds who still go to heavenly worlds after death and other certain people who do good deeds who still go to hell after death:


  "Now there is the person who has killed living beings
  here... has had wrong view. And on the dissolution of the body, after
  death, he reappears in a happy destination, in the heavenly world. But
  (perhaps) the good kamma producing his happiness was done by him
  earlier, or the good kamma producing his happiness was done by him
  later, or right view was undertaken and completed by him at the time
  of his death. And that was why, on the dissolution of the body, after
  death, he reappeared in a happy destination, in the heavenly world.
  But since he has killed living beings here... has had wrong view, he
  will feel the result of that here and now, or in his next rebirth, or
  in some subsequent existence
  
  ..."Now there is the person who has abstained from killing living beings here... has had right view. And on the dissolution of
  the body, after death, he reappears in the states of deprivation, in
  an unhappy destination, in perdition, in hell. But (perhaps) the evil
  kamma producing his suffering was done by him earlier, or the evil
  kamma producing his suffering was done by him later, or wrong view was
  undertaken and completed by him at the time of his death. And that was
  why, on the dissolution of the body, after death, he reappeared in the
  states of deprivation, in an unhappy destination, in perdition, in
  hell. But since he has abstained from killing living beings here...
  has had right view, he will feel the result of that here and now, or
  in his next rebirth, or in some subsequent existence." (Maha
  Kammavibhanga Sutta, MN 136)


Here we see The Buddha explaining the variables involved earlier kamma, later kamma, and the view at the time of death.

The person will always feel the effect their deeds in some form, but how that happens relies on many different factors.

As explained in the Lonaphala Sutta:


  "Now, a trifling evil deed done by what sort of individual takes him
  to hell? There is the case where a certain individual is undeveloped
  in [contemplating] the body, undeveloped in virtue, undeveloped in
  mind, undeveloped in discernment: restricted, small-hearted, dwelling
  with suffering. A trifling evil deed done by this sort of individual
  takes him to hell."
  
  "Now, a trifling evil deed done by what sort of individual is
  experienced in the here &amp; now, and for the most part barely appears
  for a moment? There is the case where a certain individual is
  developed in [contemplating] the body, developed in virtue, developed
  in mind, developed in discernment: unrestricted, large-hearted,
  dwelling with the immeasurable. A trifling evil deed done by this sort
  of individual is experienced in the here &amp; now, and for the most part
  barely appears for a moment." (Lonaphala Sutta, AN 3.99)


So you see there can be many people perceived as good but undeveloped in many aspects (contemplating the body, virtue, mind, discernment, heart) so any trifling evil deed they did in the past many take them to hell (or cause them to have negative experiences).

And there can be many people perceived as evil but developed in many aspects (contemplating the body, virtue, mind, discernment, heart) so many trifling evil deeds they did in the past still may not take them to hell (or cause them to have negative experiences).

There have been many genocides in history besides the holocaust, the genocide of the Jews. There have been for instance the persecution and execution of Buddhist monks by many different groups in history.

How this ties in is that there are many different variables involved in one's experiences...it does not necessarily mean that those who took birth into a region or time-period where they were persecuted and executed for no real reason are evil-doers or came from one of the three lower destinations (hell, the animal realm, realm of ghosts) although it does mean that they are exhausting their evil kamma that was caused for some reason or another (and also means that the one executing the violence is causing evil kamma).

If mankind as a whole wants violence to end all around the world we have to cause good kammas (bodily, verbal, mental) such that only good beings can exist on Earth...if you look the global homicide rate and violence around the world that time hasn't come yet...but will certainly come sometime in the future if more and more people continue doing good deeds and practicing metta (loving-kindness).