What could a nuke-armed nation achieve if it genuinely did not fear nuclear retaliation?

Great Debates
1

Let’s say that one day Kim Jong Un informs the United States he’s about to invade South Korea, and will use tactical nukes. The USA says, “Nope, South Korea is under the US nuclear umbrella,” and Kim laughs and says “Lol, we know you’re not going to retaliate because we have ICBMs that can hit Los Angeles and Chicago and you know your interceptors aren’t reliable,” and hangs up the phone. An hour later, a dozen places in South Korea turn into mushroom clouds.

Or, Russia masses for an invasion of NATO. NATO warns, “We are a nuke-armed alliance, you don’t want to do this,” and the Russian leader laugh, “Nah, we have second-strike ability, and if you use nukes you know what we’ll do to you.” Soon, Russian tanks are rolling into Warsaw. (Now, of course, in real life, Russian nuclear threats are casual and worthless, but assume in this scenario that Russia actually genuinely doesn’t fear NATO nukes one bit and is also itself perfectly willing to use nukes and everyone knows it.)

Or it could work the other way too. Say the USA announces publicly that it will do a Desert Storm type of operation to kick Russian forces out of Ukraine, and Ukraine + NATO + USA also announce they will jointly seize tens of thousands of square kilometers of Russian soil in a land grab, or maybe even seize a bigger chunk of Russian land (but stopping well short of Moscow.) When Russia, predictably, says, “Hey, we have the world’s largest nuclear arsenal!”, America and NATO laugh, “Lol no, we have ballistic-missile subs, you know you can’t take out our second-strike ability and we can make you a wasteland just with our SSBNs alone,” and then the American/NATO/Ukraine tanks begin not only retaking all of Ukraine but also pushing deep into Russian soil.

The whole basis of nuclear deterrence is MAD (mutually assured destruction.) It’s all based off of the assumption that rational actors fear being nuked in retaliation. But what would happen if a nuke-armed nation not only had robustly survivable second-strike ability, but also genuinely did not give a fuck about the risk of being retaliated against? In other words, the aggressor doesn’t fear nukes, but every other nation in the world retains their fear.

2

There’s no nation that genuinely does not GAF about being retaliated against. What would be the point of NK using tactical nukes as part of an invasion of SK if it will result in NK being obliterated. 2nd strike capability isn’t really a factor, your nation will still be destroyed. You MIGHT manage to hit LA and or SF, but your entire country WILL be wiped out.

MAD works because it is a defensive tactic, not an offensive one.

3

I’m not really sure what you are asking here. How many cities North Korea could nuke before it is struck by American ICBMs in retaliation? What is North Korea actually trying to achieve here by nuking South Korea?

4

The OP has described the situation the U.S. found itself in immediately after WWII and before the USSR (or China) acquired nuclear weapons. You’ll notice that despite no fear of nuclear retaliation, the U.S. did not nuke any of its adversaries.

5

I don’t understand the question. If a nation doesn’t care about being retaliated against, then what happens is that they get retaliated against. At which point either the leadership realizes that yes, they do actually care, or there’s shortly new leadership.

6

This sounds a bit like North Korea. The 0.01% who run the country don’t give a damn about the bottom 99.99% of the population there and know that any strikes on North Korea will hit them. The leaders who truly matter will be in bunkers.

They also know if their regime topples, that they will end up tortured, imprisoned and executed. At that point they have nothing to lose and will fire nukes most likely.

I feel like North Korea’s foreign policy is basically ‘we can do pretty much anything we want and nobody will retaliate because of what we can do to South Korea and Japan, and if they do retaliate to the point where our regime falls, we will nuke everyone on our way out’. This gives North Korea the right to break pretty much any law they want.

Having said that, this situation is also a risk of non-governmental individuals or groups gaining access to nuclear weapons. There is no state to retaliate against if that happens.

7

Or the country ceases to exist as anything other than radioactive craters (depending on who they’re provoking).

8

Not much before they get struck by nuclear weapons. Being crazy or psychopathic doesn’t make you invulnerable. You’re just guaranteeing you’ll be dealt with in some unpleasant manner.

9

Sorry, I didn’t explain well.

What I meant was: MAD seems to be exploit-able if a nuke-armed aggressor is unafraid of nukes, but everyone else retains their fear of nukes. The aggressor can get away with a certain amount of transgression because nukes force the receiving nation into an all-or-nothing proposition.

So, for instance, to use an absurd scenario, China could invade and conquer Hawaii, and then warn the United States, “If you try to retake Hawaii, we’ll nuke all of the remaining US states.” The United States would then face a choice: do we lose 1 state, or lose all 50? Given that sort of choice, America would reluctantly have to accept the limited loss and give Hawaii up.

Or, if America+NATO were to invade Russia, and Russia knew that the invading force would capture only 5% of Russian land, but go no further, then Moscow likewise faces an unpleasant choice: either accept the loss of 5% of Russia, or lose 100% of Russia. In that scenario, the loss of 5% would appear much more palatable. Of course, the aggressor would have to make it clear that its aims are limited; if America+NATO said, “We’re marching on Moscow and we’re going to overthrow the regime,” then a tyrant may say “well, if we’re going to lose our whole nation, then we might as well nuke things out.”

So, IMHO, as long as a nuke-armed aggressor 1) genuinely doesn’t fear retaliation but also 2) is smart enough to push for only limited gains, then it can get away with a significant amount of invasion and aggression that it never could if it were scared of nukes. Assuming, of course, that all other nations retain their fear of nukes (this is key to the scenario.)

10

So basically “what’s the worst a nuclear power could get away with before other nations would be have to reply in kind, kickstarting MAD and WWIII”?

11

Then what you get is other nations nuking the rogue state’s nuclear launch facilities. Because they’re afraid of nukes, and that’s what you do when you’re afraid.

12

Consider a terminal diagnosis for Kim Jong Un: a neurodegenerative disease that delivers both physical agony and cognitive disintegration. As his executive function erodes, so too does the illusion of his own legacy. The monuments, the arsenals, the dynastic lineage—all reduced to dust by the ticking clock in his own skull. In this state of paranoid lucidity, he perceives a stark equation: if his future is void, then the future of everyone else is equally void. Stripped of the fear of consequence, and devoid of any intrinsic empathy, he seizes the sole agency left to him: the timing of his own annihilation. With nothing to lose and no moral compass to consult, what material check prevents him from triggering a nuclear apocalypse purely to dictate the final punctuation mark of his existence?

So we must ask: when a leader values neither his future nor ours, does any diplomatic or military deterrent retain its power to restrain him?

13

I don’t think so. Why wouldn’t America, for example, conduct a similar limited land grab of a Chinese possession?

I don’t think the threat of a nuclear launch creates a deterrent when used as cover for some nefarious act. Our very fear would lead us to conclude there’s no such thing as a reliable, limited land grab. We must act!

14

.This is actually kind of simple. If a nation invades another they do it because they want to achieve something by occupying it. They don’t do it to provoke allies and then threaten them not to retaliate. I mean, they might do that, but the ability to do that would not be the reason they invaded in the first place. By invading, they’re looking for spoils of some sort, even if the spoils are just greater security. They would not achieve that directive if they enter a nuclear war with the allies of the nation they’ve invaded. If they were interested in engaging in a nuclear war they would strike first without warning. So if they invade their neighbor and tell their neighbor’s allies to stand down or they’ll launch nukes, they are bluffing. And competent military brass know this. Even incompetent ones probably do. These are scenarios of brinkmanship that play out in prison yards on a daily basis, albeit at a much smaller scale. When a person in prison gets shivved, it doesn’t happen after someone threatens them while waving a shiv in their face. The person who gets shivved doesn’t see it coming. There’s no hollywood dramatics involved in real life.

15

I think the implication is that in this scenario North Korea calls it a bluff and dares the US to respond, which may result in North Korea’s obliteration but will cause grievous harm to the US. The further implication is that the US will back off and let it happen because losing Los Angeles for South Korea likely will not be seen as an acceptable outcome.

Its actually an interesting question in a theoretical way, but I don’t think anyone will like the outcome in reality.

16

In those 4 years, I dont recall much in the way of adversaries the US had.

17

The USSR was absolutely an adversary immediately following WWII. The U.S. was only allied with the USSR in the first place during WWII because Nazi Germany was a greater mutual threat.

The U.S. actually did consider attacking the USSR following WWII (and did in fact conduct a disinformation campaign indicating they had the capability and war plans to attack with atomic weapons), but fortunately cooler and saner heads prevailed.

As for China, the U.S. of course supported the Nationalists during the Chinese Civil War, and when the Communists took over mainland China, relations deteriorated significantly, leading indirectly to the Korean War when China-aligned North Korea attacked U.S.-aligned South Korea.