A novel about 1960's RAF Vulcan crews attempting to make the case for continuing the use of the manned bomber by secretly penetrating Americas airspace to show how the bomber can still get through even in the age of missiles.
A passionate argument for maintaining a fleet of nuclear-capable bombers rather than relying on the all-or-nothing of ICBMs, wrapped up in fiction. The characters are a little two-dimensional, and there's no real suspense about what the protagonist is up to, given that we're told on the flyleaf, but it's well-written and genuinely had me guessing towards the end.
(The US still operates B-52 and B-2 bombers, both capable of carrying a nuclear payload.)
Supposedly Anthony Gray was a pseudonym for a much better known writer. The book is kind of a fail-safe type, about the dangers and potentialities of nuclear war. I remember it as being pretty readable but I don't remember much in the way of details.