I don't think there is actually much connection between the kind of individual fights mentioned there and organised high level violence, such as wars.

When people get angry that interferes with efficiency. Cool detachment from what what you are doing is surely necessary for an efficient sniper, someone dropping or planting a bomnb, or for a commanding officer ordering an attack, in which there are going to be heavy losses. I doubt if you get much of the kind of adrenalin rush you get in a fight from that kind of thing.

It's possible to be a fist-fighting pacifist, and what Mark described there is an example. To quote myself from a previous post: "War is about killing people you don't know with whom you have no personal quarrel, on then orders of people whom you may well not respect.

A pacifist is someone who refuses to take part in waging war. You don't actually need to be non-violent in all circumstances to be a pacifist.