A new arms race?

Sam Sifton, NY Times -  Last fall, Russia unveiled the Poseidon, an underwater drone that can cross an ocean to detonate a thermonuclear warhead. That could set off a radioactive tsunami and eliminate a coastal city. “There is nothing like this in the world in terms of the speed and the depth of the movement of this unmanned vehicle — and it is unlikely there ever will be,” Vladimir Putin said at the time. (He added that there were “no ways to intercept” it.)

Russia is also trying to place a nuclear weapon in space, American officials said during the Biden administration, where it could vaporize fleets of American satellites.

China, for its part, has tested a hypersonic missile that could follow a zigzag path and release a warhead that would be almost impossible to intercept. And it appears to have little interest in arms control until the size of its nuclear arsenal matches the ones controlled by Washington and Moscow