The land of Buudha, why is there no peace in Nepal then? That is my counter question.

Our Hindu/Buddhist belief has its own rudimentary flaws to begin with, hence we are raised that "in order for you to live in peace, you should live and let live" But how practical is that? Sounds good in terms of philosophy, but primitive in practicality.

The answer to your question, why do they kill

Si vis pacem, para bellum

It means if you want peace, be prepared for war. A stronger person is less likely to be bullied than a weak person ( peaceless, like Nepal) . Does it make sense? Is it logical? Hell yes.