There's not actually been any shooting, well, except up in the air as a warning, and most of that was from 'pro-Russian milita'. There's not that much in the way of Russian equipment in the Crimea, especially not compared to what they
could send. It's mainly still what was originally there, perhaps some more APCs and infantry than before, but otherwise still the same.
The US has sent a warship through the Bosporus, so I don't know what they're up to, hopefully they will just sit back and watch rather than try to do something daft like trying to run the Russian blockade.
In regards to a war between Russia and NATO, not likely, not over the Ukraine, the Baltic states maybe, but not Ukraine. So no need to worry about a thermonuclear exchange just yet.
