A president told reporters he wanted to “start testing nuclear weapons” while flying to meet Xi, and the timing set off alarms. We break down what it would actually take to light a test in Nevada after three decades offline, why subcritical experiments and modeling already safeguard reliability, and how treaty logic—if you test, we test—has kept a fragile peace. From the START framework to real-world launch notifications and telemetry games, we pull from lived experience in satellite monitori...