As for the tactical nuke sub-thread:
Going back to the Cold War, everyone remembers the 'MAD' thing. But few remember or know about some of the variations of this.
The Soviet Union always made a big deal over saying it would never be the first to use nuclear weapons in a war (that is in the case of a war between Warsaw Pact and NATO--the US had already got the historical first out of the way).
The US NEVER said, as far as I know, that it too wouldn't be the first, though I think Reagan in Iceland goofed around out loud with the idea because he really didn't know what policies the US was using--til someone who knew what the policies were corrected him--Margaret Thatcher and Al Haig. Of course, remember, it was Reagan who wanted to get rid of the Dept. of Energy because he associated it with Carter's efforts to get the country to start on serious energy conservation.
Anyway, the US doctrine was that their nuclear forces had 'strategic' and 'tactical' weapons. In the event of, for example, a Warsaw Pact armor invasion of Germany, if overwhelmed, US artillery would fire tactical nukes (a policy that didn't thrill Germany very much--remember the fuss over neutron bombs under Carter). The Soviet Union then said, they made no distinction between tactical and strategic, nuclear was nuclear.
This has always been one reason why lightly armored and armed airborne divisions (Army) and regiments (USMC) could brag about wielding terrible firepower--some of their artillery would have nuclear rounds available. US Navy anti-submarine ships long practiced at the tactic of dropping nukes on the Soviet subs ( a package delivered by a missile first, which then dropped down into the water, away from the ship, in order to do its work) .
The US Navy, the Army and the Air Force had tactical nukes scattered all over the world (including non-nuclear Japan, in clear violation of the US-written constitution). Supposedly, since the end of the Cold War, there has been much less deployment of these weapons worldwide--something I think was stated under Pres. Clinton. But US policy has always been neither to confirm nor deny the presence of the weapons where ANY of their forces are deployed. New Zealand had a major run-in with the US on the matter back in the early 90s, since they wanted US ships in their ports confirming that the nukes had been offloaded and weren't in NZ. Uhhh, the US won that struggle, by the way.
No doubt, absolutely no doubt, that in putting together various war scenario 'packages' for Pres. c-o-'W'-a-r-d, tactical nukes are being discussed as options. But as of yet, it is still hard to imagine any events justifying their use.
Charles Jannuzi