It is wrong to kill a man.
Or is it? What if that man has killed another?
Is it wrong then?
If yes, then what if he has killed two others?
Or three? How many shall die at his hand before we can put him to death with a clear conscience?
It is wrong to steal.
But is it wrong for a poor man to thieve bread from a rich man who stores loaves in abundance? How empty must the thief's belly be before we forgive him his crime? How full must the rich man's granary be?
There can never be one law that answers the question of what is right and what is wrong.
There is only a river of justice, steered by the impulses of men and women, Gods and Goddesses, chance and nature.