When we talk about the risks of nuclear war today, we have to talk about…computers.

Nuclear and tech experts know that all digital systems are at risk for cyberattacks—including nuclear weapons systems. That means that our own warheads, delivery vehicles, and the technology we use to control them are prime targets for hackers. The systems we rely on to detect incoming attacks are susceptible, too. These cyber vulnerabilities in nuclear weapons systems undermine the safety and security of nuclear weapons around the world.

Since the first explosion of a nuclear weapon in 1945, the world has avoided an accidental, unauthorized, or miscalculated launch. But there have been dozens of close calls—and in today’s cyber age, our luck could run out.

In this video, national security expert and former Special Advisor to the U.S. President Richard A. Clarke explains why the risk of cyber attacks on nuclear weapons systems should have us all concerned—and what we can do about it.