+1 Your first point is the textbook discussion of disarmament. You might consider referring to the Prisoner's Dilemma, which is one model that is often used in these cases.

@indigochild Thanks for the +1! I've added a bit about the Prisoner's Dilemma to my answer.

This is only really valid for situations like USSR and USA far enough apart where you'd actually have time to see the incoming missiles, figure out what's going on, and launch your own.

@DaxFohl And that's why nuclear-armed submarines exist. I can think of at least two countries off-hand whose entire nuclear arsenal is on submarines for exactly that reason. Unless you can eliminate their subs, they will still nuke you back if you nuke them first.

"The NPT is not a legally binding commitment" - this is wrong. It is binding. On the other hand, a country can leave it following certain order.

@Anixx Could you clarify in what way it is binding? I'd be happy to correct my statement.

As a much deeper analysis of MAD and why even reducing nuclear stockpiles to "just enough" to totally destroy the opponent may not be advisable, I strongly recommend chapter 10 of Thomas Schelling's "The Strategy of Conflict" first publish in 1960. (I actually recommend the whole book.) The chapter, Surprise Attack and Disarmament, points out non-intuitive consequences such as that we should focus on defending our retaliatory force rather than our cities and that larger stockpiles can lead to a more stable outcome. (1/2)

His analysis is highly simplified, as he explicitly states, and he definitely wasn't arguing for an arms race. There are other factors such as the fact that more missiles means it harder to guarantee that some don't fall into the hands of terrorists that are countervailing forces. Nevertheless his analysis is less simplistic than many others and makes clear that it isn't obviously the case that arms reduction is a good thing. (2/2)

@indigochild Thanks for the Prisoner's Dilemma link. At first I thought it was completely inapplicable, but I'm starting to see the point.

+1 ... I've also proposed an edit to touch on states that have disarmed and why disassembling isn't simple.

+1. Worth noting that no sane government would use nuclear weapons to kill millions of people, unless perhaps its own survival was threatened. For example there was zero chance of the UK nuking Buenos Aires in the Falklands War. Retaining nuclear weapons is insurance against an insane rival nuclear power.

@RoyalCanadianBandit it's also an insurance against an opponent that's strongly superior in conventional warfare - there have been many wars in which the country's own survival was threatened, and having nukes ensures that you can always get a cease-fire in such a war by threatening to use them. Currently North Korea is "uninvadeable" because of their huge military, but if they'd have a proven ability to nuke Seul and Tokyo, then they'd be uninvadeable even if they moved 90% of those soldiers to farming. If Hussein had effective WMD and means to deliver them, Iraq wouldn't get invaded as well.

Under the MAD-Concept it is also worth noting that the US-Missile-Shield initiative is, despite it´s seemingly defensive nature, seen as aggression by other nuclear powers. It would allow the US to use aggressive force against these powers without being subject to the MAD consequence.

@reirab I believe the UK is the only nuclear-armed country to rely only on submarines. The US, Russia, India, Pakistan all have air-dropped bombs, ballistic missiles and submarine-launched missiles, and Israel is believed to have the same. China has ballistic missiles and submarines; France has air-dropped bombs and submarines. North Korea is developing land- and submarine-launched ballistic missiles and it's unclear what else they have.

@DavidRicherby Ah, you're right. I forgot about France's 20 air-dropped bombs.

I'd like to expand a bit about the Prisoner's Dilemma. First, this is really an iterated game, every... lets say day, we all decide not to nuke each other. The game ends when one person defects (bombs way). Second, defecting is actually the Nash Equilibrium, the play which is better no matter what the opponent does. There is a certain inevitability about it.

@reirab That is where the comparison to PD breaks down. If you defect in PD they don't get to hit you back... unless you are playing an iterative game of course, there the best play is "first cooperate, and if someone defects do it right back". But, assuming you can hit your opponent first and disable their ability to return fire. That is more tempting.

@reirab I'm not saying it is a good idea. Ever. I am saying the stable point in PD is to defect. And eventually someone in the real world will too.

@reirab 40, though it doesn't make much difference. (According to Wikipedia, they scrapped 20 out of 60).

@DavidRicherby Ah, right again. I originally read it as "to a third" instead of "by a third."