[RobertMiller]

That's not how things work, at all. Ballistic missile defense is meant to reduce the number of nuclear warheads that make it through, not eliminate the threat entirely. Extant ballistic missile defense doesn't even come close to eliminating the threat, and that's without considering Status-6.

Consider, for instance, that there is no way in hell you could touch North Dakota with Status-6. If Russia wanted to attack missile silos in North Dakota, they would need to use their own ballistic missiles for it. Ballistic missile defense reduces the chance that they could succeed in any sort of decapitating preemptive strike. That it can't also stop a nuclear-powered torpedo is irrelevant; that's simply not what it's meant for. Other threats are/will be countered by other systems.

[bagels]

Hypersonic missiles though?

[RobertMiller]

Which kind? 'Hypersonic' is a speed regime, not a technology in itself.

Hypersonic cruise missiles are not in the purview of ballistic missile defense, unless they have a ballistic stage, in which case they might be. Hypersonic boost-glide vehicles, having a ballistic boost-stage, are countered by some forms of ballistic missile defense, but not all.

Ballistic missile defense is a defense against ballistic missiles. Not torpedoes, cruise missiles, artillery shells, nukes smuggled in shipping containers, frogmen going up a river with a SDV, or anything else. Pretty much just ballistic missiles, or at least weapons with a ballistic boost stage.

[bagels]

Right, I completely agree with you.

I was responding to this, specifically, but did not elaborate enough: "in North Dakota, they would need to use their own ballistic missiles for it"

There are a lot more ways to fly a nuclear weapon to North Dakota than just ballistic trajectories. Bombers, cruise missiles, hypersonic missiles, etc.

[_kbh_]

Russia can barely maintain the gear they have that costs orders of magnitude less than a hypersonic missile / nuclear torpedo. Whats the chances their hypersonic missiles / nuclear torpedos even work?.

[csee]

I wouldn't make any decisions on the thought that they won't work. Even if 90% of their currently deployed nukes don't work, that's still 160 deployed nukes that work, which is enough (not for outright extinction, but still). And 90% would be a high estimate given that Russia is genuinely very capable at rocket tech.