You make interesting observations. It may be that the survival instinct at the earliest evolutionary stages develops an avoidance to conflict proposition. It may be that aggression is keyed in on the rewards of aggression.

Say the capture of females from a neighboring tribe is worth the risk of death in trying to acquire them, or in modern society the wealth, mansions and power that come with being the leader of a succesful revolution.

Violence, risk and warfare, in other words, would be spurred by the development and recognitions of material rewards or compensations for such violence.

In a weird parallel I know some women who justify smoking because they would rather die a few years earlier and stay slim than live longer and be overweight. They are willing to make sacrifices for other perceived rewards.

So violence, war and competition may vary at various times even when evolutionary development is so geared towards benefits of such conflict.

Tom, for example, perceives the benefits of waging war to ward off future aggression and danger. In this sense he in no way loves violence but only agrees with military action that provides a sufficient positive benefit for more people than it harms.

It is this weighing of good/evil that we all partake in to some degree. We are forced to reaffirm our beliefs and reevaluate them in the face of new contrived experiences. Atomic warfare transformed the face of conflict but also the provided a new justification for war to prevent others from obtaining such massive future destruction potential.

Sacrifices for greater returns.

Morality meets an interesting roadblock. Is it more moral to sacrifice 10,000 to save 1,000,000 or is it more moral to avoid violence at all cost, regardless of the outcome?

Is it immoral to develop flexibility in one's maxims, or does flexibility for the greater good constitute the greater level of morality?

This is the unspoken conflict between proponents of the Iraq war and its detractors.

There are no easy answers other than to point out the certainty that everyone will have a different view on the matter.