Twenty-five years ago, my father was in South Vietnam for several months. He’d already retired from the Marine Corps by then, having served for twenty-seven years, and had started a second career in the ordnance (that is, weapons) division at Honeywell — or, as my father always referred to the company, “Honeypot,” because they kept thousands of Americans employed and safely ensconced behind white picket fences and two-car garages. At the time, Honeywell was a major supplier of antipersonnel weapons to the United States military, and had just begun work on the “automated battlefield,” a coordinated array of sensors and antipersonnel devices that could keep a given area free of enemy forces. But there were two problems with the automated battlefield: The enemy could (and did) go underground. And the sensor equipment couldn’t always distinguish soldiers from civilians, water buffaloes, large dogs, children — it simply fired at them all.