It is impossible to simultaneously prepare for war and plan for peace

I’ve heard that It is impossible to simultaneously prepare for war and plan for peace (or something like that)
Is it really true?
I’m no spirituality expert but I think that it might very well be true.
A spiritual analogy: People seem to be at their best when Gods light is shining through them. When light shines through a person there is no shadow.
A shadow is cast whenever a persons ego is presented to another person. That is why no matter how nice or sincere that person is, a shadow caused by doubt, pride, i.e. fear or ego is cast.
Enlightened beings like Jesus have been said to have a light radiating from their body. It seems to me the light would mean that God is using that person in a way that God can be seen through and in that person. There would be no shadow cast and no ego characteristics showing.
So would Jesus with Gods light disarm people with just the light? (love)
I don’t know if when Jesus was here that Gods light shown through continuously or not. I suspect that was part of the reason for his dying on the cross. If we see Jesus today maybe he won’t have any shadow and enemies will fall down before him afraid.
Maybe instead of saying it is impossible to simultaneously prepare for war and plan for peace, it should be said that it is not necessary to prepare for war at all. Peace is all that is needed.