The Mystery, Crime, and Thriller Group discussion

K, here's the deal. In my teens I read a thriller like this: The USSR (or some baddie) has defeated the US in a lightning strike. Caught us with our pants down, sucker-punched us, etc. and now rules us with an iron fist. Plan for redemption involves an agent dubbed "The Diver" (I think) who hijacks a nuclear sub and threatens to unleash nuclear armageddon on the aggressor if they don't withdraw. Does this plot ring any bells? Thanks!

It doesn't sound familiar, but it's not really my genre, sorry.
If no one here knows what it might be there is always the dedicated group:

https://www.goodreads.com/group/show/...

Good luck!
(and do come back and let us know what it was!)