The function of a nuclear warhead as a deterrent is not that dependent on whether or not it works. I'd bet enough of them do that our enemies will assume that they will be available if necessary.

We need the deterrent for the forseeable future. Unilateral disarmament has always been, and always will be, lunacy.

Environmentalists have blown (no pun intended) nuclear weapons out of all proportion to their actual effects. A limited nuclear exchange would be hell on those in the target areas, but most of the planet wouldn't even notice it. Many atomic weapons were set off in the open air years ago, almost a hundred just in Nevada, and oddly enough, we're all still here, and the glaciers didn't roll in.

I'm no tactical expert, but I personally don't think it's essential to create nuclear "bunker busters." The job can be done other ways, and we don't need any more compact bombs floating around.