[speedybird]

It seems equally unlikely to me that the Pentagon would let loose the nukes after losing a single SSN and having no other indication of an invasion. For one thing, it would probably take days to confirm the sub was sunk, and by that time the lack of an invasion should be clear. All the other American ships in the area being unscathed would also be a pretty big clue.

To be frank I'm not even sure I believe America would start a nuclear war at all even if Taiwan really were being invaded.