The deployment of 5G networks by the U.S. military will be an historic moment for today’s warfighter. From improved C5ISR [command, control, computers, communications, cyber, intelligence, surveillance, and reconnaissance] readiness and geolocation accuracy to more effective enemy engagement and perimeter defense, 5G gear will enable scalable, extremely low-latency, mobile radio platforms and an Internet of Things edge-sensor network that puts the power of real-time AI and machine learning into the hands of the combat soldier. This future state is achievable, but not without confronting a blunt reality: 5G is an open architecture designed for commercial applications and as such suffers from a great many security vulnerabilities. To build a resilient, secure, survivable 5G military communications network, we must first harden and future-proof the COTS [commercial off-the-shelf]-based hardware, software, and firmware that are the foundation of today’s civilian 5G infrastructure.