The most significant risk at this time, both Samson and Erath noted, is the potential for such a weapon to increase international tension between the US and Russia and normalize nuclear threats as a replacement for diplomacy.

“If nuclear blackmail becomes normalized as a tool of international relations, then everybody’s going to want to have the capability to do it,” Erath said. “Ultimately, you don’t make threats if you’re not prepared to carry them out, and somebody at some point is going to want to carry one out.”

He added: “And a nuclear attack anywhere in the world is a very serious thing. It’s not going to be the old Cold War mantra of destroying the world many times over; that’s science fiction. But the effects in its place, both in the neighborhood and worldwide, will still be catastrophic.” Read more