Thought is like a bubble rising to the surface. When thought is joined to will, we call it power. That which strikes the sick person whom you are trying to help is not thought, but power.
In war, as in politics, no evil - even if it is permissible under the rules - is excusable unless it is absolutely necessary. Everything beyond that is a crime.
The Vedanta recognizes no sin it only recognizes error. And the greatest error, says the Vedanta is to say that you are weak, that you are a sinner, a miserable creature, and that you have no power and you cannot do this and that.