Yea good observation. In times of peace we seem very meek and harmless but in times of war we are incredibly cruel.
It makes sense though. As an Asian individual, I'm generally peaceful but when I get angry, I tend to explode and lose control. This is because we Asians tend to pent up our emotions, accept abuse, bullying, and injustice inflicted upon us and not express anything. But when we do express them, we really express them. I mean we really really express them. This has been noticed by Chinese people introspectively examining our national character. Actually, most East Asians are like this. We seem melancholy all the time and are like robots. But when we explode, we really explode.
But yea I don't condone violence. I would rather just read about society falling apart. Or I just let off some steam by hitting the punching bag, do some shadow boxing, workout, fuck escort whores, etc....