How can internal war eliminate the literal war?

Isn’t the main reason why wars exist because of internal conflicts, phobias etc.? Couldn’t proper way of thinking eliminate wars? I see war as purely a psychological defect.

If people did critical thinking, re-invent their pre-existing values that were taught by others like church, etc. can’t there be a hope to non-violence? I’m not saying entirely but I think it could help.