Karma in Action
My favorite parable to illustrate Karma:
A shogun goes to chop off a rapist's head. The rapist says, "You fat shogun, why don't you just go cry in a corner?" The shogun feels rage well up within him as he about to strike the blade; and so, he walks away.
The next day, the shogun still must perform his duty: decapitate the rapist. And so, he returns to the criminal's house. Again, the reprobate mocks, ridicules and derides him. This time, however, the shogun feels nothing and...
The lesson here is that it is an internal reaction to circumstances that determines whether we accumulate karma in action or not. It is rising above the animal body (in yoga, the annamayakosha) and acting instead from a place of duty. The action doesn't change; our relationship to it does.
Sometimes our duty will not be pretty and seems to be at odds with "morals." We are taught that Hammurabi's 'Eye for an Eye' doesn't belong in the modern world... and yet, there are truly egregious acts of evil performed in the world. What are we to do when faced with them?
We must perform our duty, and in order not to accumulate our own Karma, we just perform it without attachment.