It's simple bro,
if people only knew and understood the consequences to their negative actions then they wouldn't do anything negative.
Wouldn't think negative. And so on....
Ignorance is the root of every problem in society and is also the root of every problem one man has (selfishness, egos, etc).
An intelligent person would know better than to be or act negative. Hinduism teaches that there is no evil, only ignorance. Jesus taught that we should love our enemies, why? For the same reason why he asked God to forgive those who killed him while he was on the cross. Because people are ignorant, that's why....
It shouldn't take religion to realize that, the best minds of our time have realized that. Einstein was known to hate war and many other scientists as well. And it might be the same reason why you appose war yourself bro. Because you know better than that....
We all know right from wrong.
It is embedded in our conscious.
(People often kill their conscious)