"Anyone know off the top of their head why such a thing might not be possible? "
Firstly, it's illegal. Secondly, you could use the capability to knock out the silos in the first place. Thirdly, how many missiles can you carry on
a sub compared to a ground installation?
In any case it's an exercise in futility. Even knocking out 90% of incoming - which would be incredibly ambitious - would not allow the US or anyone
else to 'win' a nuclear exchange.
Incidentally, perhaps the biggest difference between the US and Russia is the ability to absorb damage and keep going. The Russians lost 20m+ during
WWII and kept going; it's far from certain whether the US would demonstrate the same kind of resilience under current circumstances.
A single nuke would be enough to collapse the US economy, sending the dollar plummeting and making oil imports impossible. Where would that leave the
nation? Of course it would do the same with Russia, but the impact on people's lives would be much slighter. The Russians simply haven't got as much
to lose.


If anyone want more links they should just ask.
