I have a paragraph that I can't understand a little bit. Can you see the followings;

Some people tell fine stories of the use of atomic energy in industry, and the economies which will result. Such economies, if the world remains politically what it is now, will do nothing but harm, since they will set free a greater part of human energy for the pupose of mutual destruction.

What is the meaning of mutual, not in terms of dictionary? Does it mean human and economies? What exactly does 'mutual' mean?

I'm looking forward to get your answers.
mutual destruction = destruction of one another (by the idle humans)
Oh, I see. Thank you!