Last week, the Shadow defence secretary, Emily Thornberry, was criticised- some would say mocked- by the pro-apocalypse wing of the Labour Party after she said that there could soon be sea going drones capable of tracking nuclear submarines. The Trident supporters lined up to smugly report that such devices were impossible.

So imagine my surprise when I read this morning that DARPA has a drone submarine hunter built and ready to undergo sea trials. It’s shocking that the Armageddon apologists could be wrong. I guess they’ve put so much faith in the incredible powers of Trident, that they can’t conceive any of the ways in which the system is flawed or could be compromised.

Drone sub hunter versus not-quite-stealthy-enough sub, the future of the world at stake. I think I have to store that one away as a potential story.