..... Today these drones—hundreds of thousands of them—are the most important systems in the Ukrainian inventory. This means tactical radio jammers, which can block the signals operators use to control their drones, are the most important systems in the Russian inventory. So when Russian tanks began rolling toward the front line with a giant new jammer—actually, clusters of multiple jammers—in recent weeks, Ukrainian drone operators were interested. Very interested. If the new jammers worked, the Ukrainian operators would need to develop countermeasures. Their chance to find out came earlier this month, when a Russian T-72 festooned with jammers ran over...