Alright, suppose you (where you are the head of state of a decent nuclear power) come into certain knowledge that another state is about to switch on a Dr. Strangelove-style doomsday device, that if triggered will destroy the planet; and furthermore there is no way it can ever be disarmed.
Oh, and it’s going live in a couple of hours.
Do you pre-emptively attack the device with your nukes to prevent it from ever being turned on? I personally probably would - it would be my duty to mankind.
Given a couple of hours, I would start furiously checking my sources of information…
How good is this “certain knowledge”?
Do we have video of the head-of-state laughing maniacally while holding the device? Is his grandmother in the video, as well, saying, “Oh, <so and so>, you were always the evil one?”
It would take a lot of “certain knowledge” for me to even consider taking action in the way you’re describing.
No, but I definitely pre-emptively strike to take over their mine-shaft space.
This strategy didn’t work too well with the intelligence on Iraq’s WMDs. :rolleyes:
So you have a State that wants to destroy the planet, including itself? 
What if another State gets hold of the plans? (And so on)
How much of the planet would you destroy to save it?
Having in an earlier post pointed out the glaring flaw in this scenario, I will now state that if I had real, true, certain knowledge that the neighboring country was going to destroy the world, I would indeed take pre-emptive steps to stop it.
Of course, this sort of knowledge is nearly impossible to attain.
And after doing so I would fully expect to be invaded and seized by a neighboring country - and I would allow this, if not preemptively subject myself to international investigation. Then when they put me up for trial, if they found that I was deceived and/or hallucinated the threat, I would fully expect all parties responsible for my deception, and myself, to be tried and very possibly executed.
I would imagine that a number of calls to scientists would be taking place to see if this is feasible and why dont we have our own program, if that was the case. Second , if its going live, then someone had to have watched it being built.
If the scientists feel that its possible, or they waffle , then ya the nukes fly.
Declan
No, but I definitely pre-emptively strike to take over their mine-shaft space.
Only to, sadly, discover someone beat you to it by twenty-five minutes.
Enjoy,
Steven
I think the idea of the doomsday device is to trigger if said country is on the receiving end of a nuclear attack, not to destroy the world for no reason. There seem to be some misconceptions regarding this detail, but the doomsday device in Dr. Strangelove was supposed to function as I described.
Of course, it defeats the whole purpose if you keep it a secret.
That would depend on the weapon in question. It’s one thing to verify the existence of an engineered plague organism in a lab somewhere; it’s quite another to verify the ten mile wide black hole manufacturing facility.
Deterrence is one reason, as mentioned. Another is religion; there are people who actively want to destroy the world to bring on the Rapture. As I recall, it was Jerry Falwell who spent years trying to convince Reagan to start a nuclear war, specifically to create a general Apocalypse and kill all but the 100,000 saved who would ascend to Heaven.
Very good. We read it in the New York Times.
I also have to know with certain knowledge that they’re about to use the thing. After all, the US has the capability of turning a respectable percentage of the world to glass right now, with our nuclear arsenal - but unless we’re imminently going to use them, a pre-emptive strike against us is not particularly justified, at least not on the grounds of mere possession of horrific weaponry.
Depends. If the country in question is intending to actually use it in a few hours, then yeah, nukes away. The end result can’t be worse, can it ?
However, if as in Dr. Strangelove it’s a deterrence device, then no. But I’d spend a ton of R&D money on nanotech, hoping that my crack science team will build me some nanites to deconstruct the Doomsday Device at the subatomic level should I feel the need to. That, or make terraforming Mars the number 1 priority : blow the planet all you want, we’ve got a spare ! 
If you folks recall, back in June of 1981 Sadam Hussein had a nuclear facility almost ready to start pumping out weapons grade plutonium. The Isralis, evidently having a much better intelligence service than our much vaunted CIA, found out about it and sent some F-16s, which proceeded to bomb it into oblivion. Worked like a charm.
I must admit that they didn’t use a nuclear device, but they didn’t have to.
Don’t recall all that much about the world reaction, but seem to remember that the French were REALLY mad.
Sorry - two d’s in Saddam - ddamn it!
That does not sound like Jerry Falwell. I was acquainted with him (I was friends with his grandson in college) and I generally know his religious beliefs, and i when I knew him, which was closer to his death he would not have believed that only 100,000 would be saved. He was a rapturist believing that the those who are saved would be taken out before a bunch bad things happen.
So either this was untrue propoganda, he changed his religious views over time, or its someone else your thinking about.
Yes; 100,000 saved would be raptured is how I remember it. The rest would suffer and die. Falwell was quite evil.
Isn’t that sort of thing why we continue to support Israel? Job gets done and our hands are clean.
ETA: should I go with a ;), or should I simply duck and run? 