Biden handed Putin a list of what he considered off-limits: the sixteen sectors that the United States Department of Homeland Security designates as “critical infrastructure.” These, he warned Putin, were America’s red lines. He should know that if he crossed them—if he messed with the infrastructure that held the country together, as the ransomware actors had done with Colonial Pipeline, followed in the weeks after by an attack that disrupted one-fifth of the United States’ meat-processing capacity—the price would be high. He was not specific.
