Nuclear deterrence—the strategy of preventing attack by ensuring any aggressor faces an unacceptable retaliatory cost—rests on the credible guarantee that U.S. nuclear forces can strike under any circumstances. Traditionally, this strategy of deterrence is sustained by the nuclear triad: land-based intercontinental ballistic missiles (ICBMs), sea-based submarine-launched ballistic missiles (SLBMs), and air-based strategic bombers. The nuclear command, control, and communications (NC3) ecosystem serves as the “nervous system” that connects and animates that triad, translating raw capability into a functional deterrent. By ensuring survivable command authority and connectivity, even in the face of a surprise attack, NC3 systems provide the confidence needed to dissuade an initial strike. As a result, many officials and experts have come to describe NC3 systems as the “fourth leg” of the nuclear triad: a crucial addition to nuclear deterrence that ensures the U.S. chain of command can authorize and direct the use of nuclear weapons, whether faced with an attack, a damaged network, or a disrupted chain of command.
This report serves as a primer for understanding the systems comprising the U.S. NC3 network. It also summarizes modernization plans and explores the challenges that emerge in an increasingly uncertain threat environment, complicated by multiple near-peer nuclear-armed adversaries and a list of emerging and disruptive technologies (EDTs) growing in complexity and number by the day. Since the Cold War, new kinetic and non-kinetic capabilities have emerged to disrupt the flow of information for nuclear operations, and more states are willing to use them in pursuit of their vision for the world. In the interest of global stability, U.S. NC3 systems must remain resilient, secure, and reliable in the face of these challenges.
