American national security depends upon supply chain integrity. In today’s world, America’s adversaries often advance their goals by exploiting technological weaknesses, engaging in a range of malicious cyber activities targeted at U.S. government agencies and critical industries. Insufficient protection against the possibility of devastating cyberattacks—against the American electrical grid or command-and-control communications systems during a crisis—could have disastrous consequences for society. Yet, until recently, the United States has lacked a unified strategy to deal with supply chain vulnerabilities.