By and large, causing another human being's death is not such an easy thing for most of us to do.

This Toronto Star article talks about how militaries (and presumably others) train people to overcome that natural reticence. Some excerpts:

Peter Bradley, associate chair of the war studies program at Royal Military College, told last week's (Couchiching) conference that people carry within them both an aversion to killing and a predisposition for it.

"Almost everyone can be conditioned to kill," he said. "Most of us are averse to it, and will do it only with great reluctance. And we experience great remorse afterward."

Bradley outlined four conditions that enable what he called "normal folk" to kill.

The first condition is distance. "The closer the killer is to the victim, the more resistant the killer will be," he said. "The more the potential killer recognizes the victim's humanity, the more difficult the killing becomes."

This distance can be found both in the physical space between killer and victim, and inside the killer's mind.

In terms of physical space, Bradley cited studies that show that bomber crews that never actually see their enemy experience less remorse after killing than soldiers who fight in close quarters.

Distance from a victim can be achieved psychologically by focusing on an enemy's religious or racial differences. And Bradley added that killing is easier if the killer sees her victim as less than human.

"Examples along this vein include Slobodan Milosevic, who called Bosnian Muslims `black crows,' and Rwandan Hutu leader Leon Mugusera, who called Tutsis `cockroaches.'"

The second condition that enables a person to kill, Bradley said, is that a legitimate authority orders it.

"Many veterans report that the primary reason they fired at the enemy is that their officer ordered them to fire. There are many historical accounts from leaders who state they had to continually order their soldiers to fire at the enemy," Bradley said.

The third condition is a moral justification for the killing.

"Soldiers need to be able to believe that the killing they are involved in is not murder," Bradley said.

This is where a warrior code comes into play.

"Because there is such a strong taboo against killing another human, soldiers who are required to kill in turn need a special moral framework which authorizes them to kill and specifies who can be killed, when can they be killed and how they may be killed."

The final condition that enables a person to kill is group pressure.

"Bonds that are created in military units are so strong that individual soldiers are reluctant to let the group down. If there is strong support in the group for killing the enemy and the group is nearby, the individual will feel a strong compulsion to conform to the group pressure to kill," Bradley said.

In the Second World War, artillery crews had no problems lobbing shells at an enemy that only existed as grid co-ordinates.

But 80 to 85 per cent of soldiers in foxholes during that conflict didn't shoot at the enemy unless they were under attack.

Slackers, cowards or normal?