Three bits of evidence here make me question this WW3 stuff.
1) No radio contact for 4 days
2) No radio contact upon surfacing.
3) The sub exploded.
The facts could be explained by a massive electrical surge as the result of a nuke containment failure...which isn't too absurd a guess given Soviet-era quality control. Not that the doomsday scenario isn't possible--just that it seems a more unlikely reason for those facts. Anyone know if the explosion was radioactive beyond simply reactor leaks after a sub sinking?
Except that it appears to have been a diesel - electric boat (Golf), which would fairly definitively rule out a reactor failure.