More than 100 executives of robotics and artificial intelligence companies have signed an open letter to the United Nations Convention on Certain Conventional Weapons to preemptively ban autonomous weapons. Several countries are developing these killer robots, similar to self-driving cars, to locate and eliminate targets without direct human intervention.

Among the signatories is Elon Musk, head of SpaceX and Tesla. Musk, a critic of artificial intelligence, says killer robots are “potentially more dangerous than nukes.” Human Rights Watch heads the Campaign to Stop Killer Robots. It says this technological development is the third revolution in warfare, after gunpowder and nuclear weapons. To discuss, we’re joined by Bonnie Docherty, a senior researcher in arms development at Human Rights Watch.