The code is still needed today, French says.
Thousands of U.S. soldiers returning from wars in Iraq and Afghanistan are struggling with post-traumatic stress disorder. Some have seen, and have done, things that are unfathomable.
A study of Vietnam veterans showed that those who felt as if they had participated in dishonorable behavior during the war or saw the Vietnamese as subhuman experienced more post-traumatic stress disorder, French says.
Drone warfare represents a new threat to soldiers' humanity, French says.
The Pentagon recently announced it would award a new Distinguished Warfare Medal to soldiers who operate drones and launch cyberattacks. The medal would rank above the Bronze Star and Purple Heart, two medals earned in combat.
At least 17,000 people have signed an online petition protesting the medal. The petition says awarding medals to soldiers who wage war via remote control was an "injustice" to those who risked their lives in combat.
Outgoing Defense Secretary Leon Panetta defended the new medal at a February news conference.
"I've seen firsthand how modern tools, like remotely piloted platforms and cybersystems, have changed the way wars are fought," Panetta says. "And they've given our men and women the ability to engage the enemy and change the course of battle, even from afar."
Still, critics ask, is there any honor in killing an enemy by remote control?
French isn't so sure.
"If [I'm] in the field risking and taking a life, there's a sense that I'm putting skin in the game," she says. "I'm taking a risk so it feels more honorable. Someone who kills at a distance -- it can make them doubt. Am I truly honorable?"
The German pilot who took mercy
Revenge, not honor, is what drove 2nd Lt. Franz Stigler to jump into his fighter that chilly December day in 1943.
Stigler wasn't just any fighter pilot. He was an ace. One more kill and he would win The Knight's Cross, German's highest award for valor.
Yet Stigler was driven by something deeper than glory. His older brother, August, was a fellow Luftwaffe pilot who had been killed earlier in the war. American pilots had killed Stigler's comrades and were bombing his country's cities.
Stigler was standing near his fighter on a German airbase when he heard a bomber's engine. Looking up, he saw a B-17 flying so low it looked like it was going to land. As the bomber disappeared behind some trees, Stigler tossed his cigarette aside, saluted a ground crewman and took off in pursuit.
As Stigler's fighter rose to meet the bomber, he decided to attack it from behind. He climbed behind the sputtering bomber, squinted into his gun sight and placed his hand on the trigger. He was about to fire when he hesitated. Stigler was baffled. No one in the bomber fired at him.
He looked closer at the tail gunner. He was still, his white fleece collar soaked with blood. Stigler craned his neck to examine the rest of the bomber. Its skin had been peeled away by shells, its guns knocked out. He could see men huddled inside the plane tending the wounds of other crewmen.
Then he nudged his plane alongside the bomber's wings and locked eyes with the pilot whose eyes were wide with shock and horror.
Stigler pressed his hand over the rosary he kept in his flight jacket. He eased his index finger off the trigger. He couldn't shoot. It would be murder.