In the nineties, friendly fire became a public relations concern for the military. Thirty-five American soldiers, almost 1 in 4 of those killed during Desert Storm, died by friendly fire; 72 were wounded in those exchanges. Three-quarters of all American Abrams tanks and Bradley Fighting Vehicles destroyed or damaged in the war were taken down by the friendly fire. In one incident, a week after Hayles was relieved of his command, 6 U.S. soldiers were killed and 2  were wounded when two clusters of American armored vehicles began shooting at each other. The mistaken killing of combat allies has afflicted military forces for as long as humans have been fighting wars. In the 413 BC battle of Epipolae, during the Peloponnesian War, the Athenian army launched a nighttime assault on Syracusan forces, relying on code words to identify one another in the dark. It didn’t work. Syracusan troops overheard the password and began shouting it themselves. Mayhem ensued, with scores of Athenian soldiers killing one another. In Colonial America, no less a warrior than George Washington was involved in a friendly fire incident.

In 1758, during the French and Indian War, Washington, then an officer in the British army, led a detachment of infantry to seize a hill near present-day Latrobe, Pennsylvania, from French troops. The enemy fled as dusk fell, but a second British detachment stormed up the other side of the hill. In the ensuing skirmish, between thirteen and forty British and colonial soldiers were killed. Later, during the Civil War, Confederate general Stonewall Jackson was mistakenly shot by his own men outside Chancellorsville, Virginia, in 1863, with the resulting injuries contributing to his death a few weeks later. During the 1944 invasion of France, Allied aircraft had stripes painted on the top and bottom of their wings for positive identification by friendly forces. Sadly, the Allies’ ground forces lacked similar protective markings. In one incident, American bombers struck friendly troops in Normandy, wounding

490 U.S. service members and killing 111 others. Among the dead was Lieutenant General Lesley McNair, the highest-ranking American soldier to die in World War II. The recurrence of friendly fire incidents over the past century of American warfare, from World War II to the Vietnam War to today’s ongoing “forever war” in Afghanistan, should have come as no surprise to the Army. At the National Training Center, in Fort Irwin, California, controllers had been tracking every simulated shot fired by individuals, vehicles, and aircraft in intensive war games. In the years of mock combat preceding Desert Storm, a quarter of all shots fired during deliberate attacks struck friendly forces. But Big Army—the bureaucratic network of commands and directorates and fiefdoms, and the old bulls who preside over it—has long been skeptical of efforts to reduce the friendly fire. As General Gordon Sullivan, a tank commander and Army chief of staff, told an interviewer in 1993, “Friendly fire has always been with us . . . we cannot fix it in any kind of absolute sense.” A year later, two U.S. fighter jets misidentified and fired at two American helicopters over northern Iraq, shooting both down and killing all 26 passengers.

So, when Hayles presented his preliminary design for Flashlight, Big Army—true to form—decided not to implement it. The Army spent a few years attempting to develop other technologies but never fielded a comparable system to address friendly fire. With Flashlight stalled, Hayles tried to move on. He worked as a stockbroker, then founded and codirected the Arthur M. Spiro Institute for Entrepreneurial Leadership at Clemson University, in South Carolina. He made a good living as a management trainer. But his heart and mind remained stuck on the problem of friendly fire. Hayles was convinced he had the answer and that another war would needlessly kill more Americans. On that point he was relentless—he told nearly everyone he met about it. “I took quite a bit of abuse for it,” he told me with a throaty chuckle. Hayles’s prediction was correct. As American fighters swarmed into combat in Afghanistan and Iraq, friendly fire incidents proliferated. In late 2001, a U.S. airstrike in Afghanistan killed three American Special Forces, soldiers, injuring and nearly killing Hamid Karzai, who had recently returned from exile to be installed as Afghanistan’s next president. Several weeks later, in 2002, an American gunship mistakenly strafed a convoy in Afghanistan, killing the U.S.

Special Forces soldier. That same year, a U.S. fighter jet killed four Canadian soldiers with a laser-guided bomb. In March 2003, two U.S.“Warthog” attack planes responded to a call for help from a Marine company pinned down by Iraqi fire. In two passes, the jets killed several Marines they were supposed to help with missiles and gunfire.