This was highly embarrassing though I doubt it changes the equation of nuclear deterrence. Even if only half the trident are functional, no nation in its right mind will want half of the UK ICBMs heading their way. Even if you think you can shoot down most of them. It only takes a handful to flatten your largest cities.

Some loose thoughts on Trident

- Yes, Minister was a prescient show

- Trident is the UK's only nuclear deterrent.

- While the UK fired them, they are taken from a common US-UK pool of interchangeable missiles.

- NATO governments are on the open side. Failures are likely to be made public.

- It is, of course, embarrassing