In late June, an Iranian missile knocked a U.S. unmanned aerial vehicle (UAV) on a reconnaissance mission out of the sky and into the Gulf of Oman. The shootdown sent ripples of concern throughout the Persian Gulf that the incident could lead both countries down a path to greater conflict. But the U.S. military response barely made a splash. That's because instead of a conventional airstrike against Iranian forces, the U.S. response came in the form of a cyberattack targeting missile command and control systems of the Islamic Revolutionary Guard Corps. That response heralded a fundamental shift in the U.S. approach to cyberwarfare. The likely tactical objective of the retaliation was to degrade Iran's ability to carry out similar attacks. It also had a strategic component — deterring it from similar actions.