Michael Brown, director of the Defense Innovation Unit (DIU) within the U.S. Department of Defense, declares war rather matter-of-factly. "It's just not war in the way we typically think," says the longtime Silicon Valley executive who transitioned into government service in 2016. But when adversaries get to the point of "shutting down pipelines and creating other damage," he says, you're seeing the "kinetic effects of cyber."

When Brown and I chat in August—at a picnic table in a glade of cedar trees behind a tan brick building in Mountain View, California, that houses both the 341st Readiness Division of the U.S. Army and the DIU—news continues to dribble out about the extent of the 2020 SolarWinds hack. The event involved a group reportedly backed by the Russian government that compromised networks of a number of U.S. government agencies, including the Department of Energy and the National Nuclear Security Administration. A couple of weeks earlier, Secretary of State Antony Blinken, along with a coalition of U.S. allies, accused China of engaging in cyber espionage, and the U.S. Department of Justice charged four Chinese nationals with being part of a global hacking campaign targeting companies, government agencies, and universities. Chinese officials vehemently denied the charges.