PICATINNY ARSENAL, N.J. -- A 19-year-old Soldier in Afghanistan has nightmares when he killed a young boy attempting to shoot him in a firefight.

"Killing to that 19-year-old is the ultimate taboo experience and being around death sometimes brings on guilt but the Soldier didn't do anything wrong," said Lt. Col. Peter Kilner.

Kilner is a 1990 graduate of West Point and director of military academy's Center for the Advancement of Leader Development and Organization Learning. Kilner spoke June 24 to nearly 100 military and Picatinny employees at the Lindner Conference Center on the topic of "Morality of Killing in War." Kilner served in a variety of infantry assignments before being selected in 2002 to serve permanently on the U.S. Military Academy faculty.

An instructor of ethics and military science, Kilner has deployed multiple times to Iraq and Afghanistan, interviewing more than 370 junior officers about their most challenging leadership experiences.

"Those who are involved in the killing that takes place in war should be under the moral justification of killing in war," Kilner said. "Whether we vote for leaders who commit the U.S. military to war, or we design the weapons or train the Soldiers, or actually pull the triggers, we share in the responsibility for that killing and we should understand its moral justification," he added.

Kilner concluded that American service members should view themselves as a policeman, intervening between the victim and aggressor and must be the "good guys when fighting a just war."

"The moral principles that justify the use of lethal force by police officers are the same principles that justify killing in war," Kilner said. "In short, people who threaten to harm the innocent thereby forfeit their own right not to be killed. A threat—whether an armed robber or an aggressive nation's Soldier-may be permissibly killed to protect those they threaten," Kilner added.

Have U.S. Soldiers intervened when an unjust order was morally unacceptable? Kilner cited the example of U.S.Army Warrant Officer Hugh C.Thompson, Jr., a helicopter pilot who witnessed a large number of dead and dying civilians in the village of My Lai during the Vietnam War.

Thompson landed his helicopter and saved at least 10 Vietnamese civilians. He was cited with the Distinguished Flying Cross and later the Soldier's Medal, the highest Army award for bravery not involving direct conflict with the enemy.

An author and co-author of 23 articles and books on leadership, organization learning and ethics, Kilner has a master's degree in philosophy from Virginia Tech and a doctorate in instructional systems design from Penn State.