In an alternative earth, or just a few decades from now, someone was able to make a breakthrough in nuclear bombs. Developing a way to make the radiation be nullified by its extreme chain reactions or just dissipate it so quickly that the exposure to the fallout is almost inoffensive).

The today's world accord on thermonuclear weapons ban is basically done due to the cheer amount of destruction and post-destruction the blast and the fallout would cause. A literal apocalypse that would cover the skies in ashes and lethal radiation.

But, the second isn't a problem anymore in this scenario. Thermonuclear bombs are now "safe" to use.

I know that even though they don't kill everyone with the fallout, they still have the potential to send the entire civilisation back to the iron age. After all, we have a pretty delicate infrastructure in the entire world, and so, these would be the first targets of any country. And the resources available are only obtainable using modern technology.

So, taking those things in consideration, do you think this pact of non nuclear aggression would still be applied, or they would just press the button and send everything to hell?

  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – L.Dutch
    Commented Apr 2, 2021 at 2:34
  • $\begingroup$ If they did not release radiation, how would they destroy anything? Pretty useless bomb... $\endgroup$ Commented Apr 2, 2021 at 6:14
  • $\begingroup$ @MartinJames Pressure and heat, same as every non-nuclear bomb. A 10 megaton nuke that doesn't release radiation is still the equivalent of 10 million tons of TNT. $\endgroup$
    – Ray
    Commented Apr 5, 2021 at 19:28
  • $\begingroup$ The pressure is raised by the heat. The heat is generated by radiation from the overall breaking of the strong nuclear force. The heat does not leave the bomb by conduction or convection:) $\endgroup$ Commented Jul 10, 2022 at 21:57

8 Answers 8


The answer probably isn't as exciting as you'd hope.

The world pretty much as it is now.

Military generals have wanted the real-life answer to this question. As such, they commissioned military scientists to create exactly this.

The result: The Thermobaric bomb. It gives an explosion just shy of a small nuke but a cluster of 20 of the FOAB (Russia's biggest Thermobaric) would yeild a 1 kiloton blast. (Even 1 FOAB forms the beginnings of a mushroom cloud.) That means the Thermobaric is capable of destruction that can compare to a nuclear blast. On the flip side, they can be reduced in size to a very small size as well.

Thermobarics are generally used at smaller than their max size. This is because militaries prefer surgical strikes rather than massive strikes. (Testing the latter is good for intimidation, but that's about it.) Because, as far as pure destructive force, like nukes, there's enough thermobaric weaponry to render Earth unlivable. We just don't use it because the Earth can only sustain so many blasts before our atmosphere becomes deadly from just the dust. So the amount of explosions in the world has to be fairly limited to keep humanity alive.

To put in a different perspective: Earth and humanity all together acts as one super-organism. And you can only hit yourself with a crowbar so much before you die.Sure, if your leg needs amputated, that's worth considering, but using amputation each time you get an itch is a short-path to death.


Construction Nukes

If they were clean, nukes would be used for construction. Dams could be built, rivers relocated, mountain passes created.

enter image description here

Lake Chagan was created by the Soviet Union using nukes for this purpose but the radiation wasn't understood properly and they got left with a lake nobody can use. A politician who claimed it was safe went for a swim in it and died of cancer a few years later.

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    $\begingroup$ What is the name of the politician who died of cancer? $\endgroup$
    – Golden Cuy
    Commented Mar 31, 2021 at 10:32
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    $\begingroup$ @AndrewGrimm Efim Slavsky was the Minister of Medium Machine-Building Industry at the time, which is the position referred to in the article so he's presumably the person that can be seen in the video. However he didn't die until 1991 and I haven't seen any sources that claim he had cancer. $\endgroup$ Commented Mar 31, 2021 at 14:36
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    $\begingroup$ @HyperdriveEnthusiast So in other words it's just another radiation boogeyman urban legend, similar to the bridge of death and the idea that the 3 guys who waded in water under the Chernobyl reactor died of radiation poisoning... $\endgroup$
    – stix
    Commented Mar 31, 2021 at 16:25
  • $\begingroup$ According to Wikipedia (and a few pictures on Google), fish live there, and in 2018 a David Farrier swam there for a documentary. However I'd assume the radiation did impact some things, and the soviets abandoned the project after other tests did turn out more catastrophic. $\endgroup$ Commented Mar 31, 2021 at 21:34
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    $\begingroup$ @lilHar, it's more "a region in the interior" than "a region at the top", since the point of that safer argument is to have water above you as a shield from cosmic radiation. However all of that assumes all the radioactive nuclei stay where you placed them, which is reasonably fine if they're sealed inside canisters before put in water, but less true for rubble created by an explosion — anything soluble will be spread out evenly by the water. And radioactive nuclei have a nasty habit of transmuting. $\endgroup$
    – Lars H
    Commented Apr 1, 2021 at 8:33

Everyone declares war on everyone else.

All jokes aside, ultimately clean nukes probably won't change the equation much.

Without the possibility of turning the world into a radioactive wasteland, it would seem like the use of nuclear weapons would become more politically acceptable, but...

Thermonuclear weapons are actually extremely clean (relatively speaking) and won't generate radioactive fallout if the fireball doesn't touch the ground. The Tsar Bomba test was actually one of the cleanest nuclear weapons ever detonated (that of course would change if it was detonated at its full 100 MT design yield).

Purely clean fusion bombs that don't use a fission primary are a theoretical possibility and have been researched heavily, but there are still engineering challenges that remain. Most theories involve muon catalysts or explosive pumped magnetic fields to compress the fusion fuel.

If the USA, Russia, or China did succeed in creating such a clean weapon, it's unlikely they would be public about it to avoid triggering an arms race or create tensions that could lead to a preemptive attack (after all, radioactive fallout is the main political problem surrounding nuclear weapons, even if it is a red herring).

But at the end of the day, it's unlikely that even if all sides knew of and had these clean nukes that things would change for one simple reason: Mutually Assured Destruction.

MAD actually works quite well when state actors are rational, as is clearly shown from the Cold War's lack of an actual nuclear conflict. Clean nuclear weapons are still devastating nuclear weapons, and a full on assault between two nations would still leave them in tatters within minutes, so the deterrent effect, which is what nukes are really designed for, remains, even if the nukes are clean.

However, what is a more dangerous proposition is if all nuclear weapons were magically removed from the planet. This is the true "Everyone declares war on everyone else" situation, as it returns us to a situation where wars between great powers become winnable.

The USA, Russia, and China would be far more likely to get into a conventional war knowing there was no possibility for it to go nuclear. Similarly, smaller states without nuclear weapons might be more tempted to take on larger states with them, knowing that the possibility of mass casualties from nuclear attack no longer exist.

Ultimately, it is the destructive capability over time states can bring on each other that acts as a deterrent. This is very evident in the situation on the Korean peninsula. Even without nuclear weapons, the fact that Pyongyang can absolutely devastate Seoul with artillery attacks has been a major deterrent for action from the South and the USA for decades. The fact that North Korea has been able to produce nuclear weapons is more for allowing it to force concessions out of world powers (after all, you can ignore artillery on a border that is ineffective beyond 30 miles or so, but not the possession of deliverable nukes that can destroy cities on a global scale).

There is also the prestige of being a nuclear power, as evidenced by the joke: "What do you call a country with nuclear weapons?" "Sir."

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    $\begingroup$ Very good answer. $\endgroup$
    – fartgeek
    Commented Mar 30, 2021 at 22:34
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    $\begingroup$ Sums it up: MAD doesn't rely on the nukes producing radioactive fallout, it relies on the fact that most nations involved can smash civilisations back to the stone-age in a matter of half an hour or so. Making the nukes clean just means the survivors have a little less to worry about. What I'm not convinced about is that it would meaningfully change the status quo. I doubt we'd all go to war if radiation was no longer a factor. $\endgroup$
    – Ruadhan
    Commented Mar 31, 2021 at 10:11
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    $\begingroup$ I would also disagree with the "all nukes magically vanish == war" thesis. The superpowers are more than capable of smashing a country back into the stone age without nuclear weapons. It would be a more grueling form of MAD, but MAD doesn't need nukes. $\endgroup$
    – jdunlop
    Commented Mar 31, 2021 at 17:05
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    $\begingroup$ @jdunlop Your idea that the superpowers can smash a country back to the stoneage without nukes is flawed. Only the United States has any real power projection outside of nuclear weapons. Neither the Russians nor Chinese have the ability to target ICBMs accurately enough to make them useful without nuclear warheads, nor can they deploy troops on a global scale for any kind of sustained campaign. $\endgroup$
    – stix
    Commented Mar 31, 2021 at 17:26
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    $\begingroup$ You're not considering the fact that pure fusion bombs, if they are possible at all, will most likely be able to scale down to the upper end of conventional ordinance, i.e.~10-20t TNT equivalent while being much smaller. If you can fit a radiation-free micro-nuke with a MOAB equivalent explosive power into an artillery shell or the warhead of a Hellfire missile, I think they will get used. And then it's off to the slippery slope, $\endgroup$
    – Eugene
    Commented Apr 1, 2021 at 7:59

You build nuclear rockets because nuclear rockets literally rely on a nuclear explosion to operate.

The technology may or may not be applicable to conventional nuclear reactors since those rely on a controlled reaction and not an explosion, but if it is applicable, you build those too.

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    $\begingroup$ I don't think this would really deal with the concerns that kept Project Orion as a pipedream. Aside from issues with pusher plate construction, if I'm reading the OP correctly, the explosions are clean, but radioactive materials are still radioactive until detonated. If you have a Challenger-style disaster with literally tons of purified uranium/plutonium on board, you've just distributed a whole mess of radioactive material across the Earth below (maybe at Challenger's height of 20 KM it would spread enough to be safe, but an explosion on the launchpad means you need a new launching site). $\endgroup$ Commented Mar 31, 2021 at 12:48
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    $\begingroup$ A controlled reaction is just an explosion in slow motion. The entire point of nuclear weapons design is to make the reaction controlled for as long as possible before the reactor disassembles itself. :P $\endgroup$
    – stix
    Commented Mar 31, 2021 at 16:53

You're the author - what do you want to happen?

If you want the status quo of MAD to be maintained, stix's answer gives a good argument that it could be.

If your story needs a world without MAD clean nukes will be a good start, and with a few other elements in your alternative history you could come up with a plausible explanation.

There's quite a bit of cold war thinking asking whether you could have a "limited nuclear war" - which was an important question if, say, the Soviets invaded France with conventional forces that outnumber French forces ten-to-one. Could France use nuclear weapons only inside its own borders, or only against military targets within a certain distance, or only weapons of a certain size, without triggering the end of the world?

Their conclusion was 'maybe' - thankfully, they didn't test that.

What you need to do is remove the dividing line between small nuclear weapons and large conventional weapons.

  • Part of that will be in public opinion: You need the clean tech from the start, so a dread of nuclear weapons never develops in the minds of the public.

  • You'll also want your clean weapons to be so clean that, other than the size of the explosion, they're almost indistinguishable from conventional explosives.

  • Then you'll want an established precedent of small nuclear weapons - nuclear artillery shells, for example, barely more powerful than conventional shells - having been used in war. Maybe they're also used in civil construction projects too.

This way, it'll be a lot harder for MAD to develop into a stable system: Instead of having a clear line ("any nuclear attack") the line would be much fuzzier - inviting both sides to test one another, edging nearer and nearer to destruction.


Nuclear fallout isn't the only reason MAD deterrence exists, the non-fallout related destruction caused by the explosion is immense on its own merits and would likely still prevent war-like engagements. The other factor to consider is the amount of power these capability gives nations the USA might not agree with on various terms (such as Iran and North Korea). It's likely the main reason these armaments are sought after by these nations is to be a power broker and as leverage against other nations. We don't use generally use our highest caliber weaponry now-a-days anyway. The nuke would still be a viable weapon without the fallout for any nation's arsenal. War is just another political / diplomatic tool. Another consideration is the type of energy negation we're talking about here... Fission bombs are different than fusion bombs and emit different types of radiation at different levels.


scientific breakthrough

The radiation shielding has many useful applications:

  • nuclear powered cars
  • nuclear powered rockets (practical space travel in the solar system)
  • small (maybe household) nuclear plants (might fit in a dystopian world too)

The technology used for that might also have a dozen applications:

  • better solar panels with 100% absorbtion rate
  • spy planes absorbing all radar pulses
  • total heat shielding (just got reminded of Asimov's David Starr, Space Ranger where the hero has similar tech)

The science behind it might also have other tech uses, depending on how you explain it:

  • cheaper / smaller semiconductor technology
  • more efficient energy storage
  • quantum computing
  • FTL travel
  • FTL communication
  • $\begingroup$ Is radiation really a significant factor in preventing the usage of nuclear power for space travel? You have tons of radiation in space anyway. Unless you mean something like using actual nuclear explosions for propulsion, but even then I'm not convinced it would make a significant difference. $\endgroup$
    – tomasz
    Commented Mar 31, 2021 at 20:35
  • $\begingroup$ Well, anything can be explained. What'bout using a fission reactor's radiation (redirected with the new tech) as a propulsion? $\endgroup$
    – Uncle Dino
    Commented Apr 1, 2021 at 18:11
  • $\begingroup$ @tomasz Check project Orion. $\endgroup$
    – vguberinic
    Commented Apr 1, 2021 at 21:09
  • $\begingroup$ @vguberinic: Quoting my original comment: "Unless you mean something like using actual nuclear explosions for propulsion". $\endgroup$
    – tomasz
    Commented Apr 2, 2021 at 11:30

No More MAD

If you mean no radiation also removes the electromagnetic pulse (EMP), then that changes the entire equation for warfare. One is left with catastrophic blast damage but no direct effects outside the bombed area. Smaller nukes then start to look like big conventional explosions, and the threshold for using nukes would be reduced.

A recent article in the Bulletin for Atomic Scientist places the risk of nuclear war at about 1% per year. If you are young, that means you will be at a 50:50 chance by sometime in your later years. You would never know this from our journalists and news media. In their quest to "sell soap" they focus on sensational matters, most of which are trivial compared to nuclear war. Recall that the media was discussing Gary Hart's love boat when 911 occurred.

Your "no radiation" scenario probably would have meant that the Cuban Missile crisis would have gone off. We would have used small nukes in Vietnam. Someone might now take out the Iranian facilities. Your scenario is scary.

An interesting caveat is that some of the targets for your radiation free nukes would release radiation: nuclear power plants, isotope refinement facilities, etc.

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    $\begingroup$ Eliminating radioactive fallout from nuclear weapons does not negate their immense destructive power, and thus doesn't negate MAD. $\endgroup$
    – stix
    Commented Mar 31, 2021 at 17:56
  • $\begingroup$ Yes, the cities might be under MAD, but you can't blast all the rural areas. $\endgroup$
    – Youvan
    Commented Mar 31, 2021 at 18:05
  • $\begingroup$ Absolutely. The deterrent of nukes is the radiation, people have been cheerfully burned at the stake, or not so cheerfully, crucified, just to make what they felt was the right point. FOAB, you literally go out in a blaze of glory. Remember Litvinenko? How could you not? The guys who got to him sloshed it all over the plane, at the Emirates, all over London really, and dosed him so bad that they saved his family, a little less and they would have died beside him, he was hot as an oven. Everything he used was useless. $\endgroup$
    – chiggsy
    Commented Apr 3, 2021 at 5:29
  • $\begingroup$ They did not even know at first, he easily could have wiped out the medical team, and man oh man did that polonium do the trick, he was a solid dude, at first but his life ran out of him like pee pee runs out of a a drunk college girl squatting in the alley before she catches a cab home. Literally the opposite of a blaze of glory. Masterstroke by Putin. MAD was something we were ready for, but absolutely we were not ready or rando russians jetting in with jars of hot sauce. Even when we pictured a dirty bomb, it was a suitcase! Not a mason jar, like it was 'shine! $\endgroup$
    – chiggsy
    Commented Apr 3, 2021 at 6:01

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