I have spent four decades keeping the lights on. After Sept.11, 2001, I directed security research and development for the electric utilities of North America. Everything I know rests on one conviction: A power grid is a life-support system, and defending it is defending the people who live on it. Last month, my two countries — the U.S. and Iran — collided inside that conviction. The United States, where I have lived and built my life's work since 1978, began systematically destroying the power grid of Iran, where I was born. An Iranian-born professional named Nakisa Farrokh Seresht described what that destruction feels like from inside a family. Her mother's electricity in Iran is now cut for two hours every day, she wrote on LinkedIn. Summer temperatures approach 45 degrees Celsius. Homes depend on air conditioning to survive the heat, and high-rise buildings depend on electric pumps to move water. When the power stops, cooling and water stop with it, and she ended with a sentence I have spent my career trying to teach: “Electricity is not a luxury; it is a basic human necessit