This is a blog post, not a research report, meaning it was produced relatively quickly and is not to Rethink Priorities' typical standards of substantiveness and careful checking for accuracy.
This post is a shallow exploration of some technological developments that might occur and might increase risks from nuclear weapons—especially existential risk or other risks to the long-term future. This is one of many questions relevant to how much to prioritize nuclear risk relative to other issues, what risks and interventions to prioritize within the nuclear risk area, and how that should change in future. But note that, due to time constraints, this post isn’t comprehensive and was less thoroughly researched and reviewed than we’d like.
For each potential development, we provide some very quick, rough guesses about how much and in what ways the development would affect the odds and consequences of nuclear conflict (“Importance”), the likelihood of the development in the coming decade or decades (“Likelihood/Closeness”), and how much and in what ways thoughtful altruistic actors could influence whether and how the technology is developed and used (“Steerability”).
These tentative bottom line beliefs are summarized in the table below:
Category | Technological Development | Importance | Likelihood / Closeness | Steerability |
Bomb types and production methods | Radiological weapons | Medium | Medium/High | Medium/Low |
| Pure fusion bombs | Medium | Medium/Low | Medium | |
| High-altitude electromagnetic pulse (HEMP) | Medium | Medium/Low | Medium/Low | |
| Neutron bombs | Low | Medium/Low | Medium | |
Methods for production and design | Atomically precise manufacturing (APM) | High | Low | Medium |
| AI-assisted production/design | Medium/High | Medium/Low | Medium | |
| Other developments in methods for production/design | ? | ? | ? | |
Delivery systems | Hypersonic missiles/glide vehicles | Medium/Low | Medium/High | Medium/Low |
| More accurate nuclear weapons | Medium | Medium | Medium/Low | |
| Long-range conventional strike capabilities | Medium/Low | Medium/High | Medium/Low | |
Detection and defense | Better detection of nuclear warhead platforms, launchers, and/or delivery vehicles | Medium/High | Medium/High | Medium/Low |
| Missile defense systems | Medium | Medium | Medium/Low | |
AI and cyber | Advances in AI capabilities | Medium/High | Medium/High | Medium |
| Cyberattack (or defense) capabilities | Medium/High | Medium/High | Medium | |
| Advances in autonomous weapons | Medium | Medium/High | Medium | |
| More integration of AI with NC3 systems | Medium | Medium | Medium | |
Non-nuclear warmaking advances | Anti-satellite weapons (ASAT) | Medium/Low | Medium | Medium/Low |
| “Space planes” and other (non-ASAT) space capabilities | Medium/Low | Medium | Medium/Low |
Note that:
In 2021, Michael did some initial research for this post and wrote an outline and rough notes. But he pivoted away from nuclear risk research before having time to properly research and draft this. We (Michael and Will) finished a rough version of this post in 2022, since that seemed better than it never being published at all, but then didn’t get around to publishing till 2023. As such, this is just a very incomplete starting point, may contain errors, and may be outdated. It could be quite valuable for someone to spend more time:
See also Research project idea: Technological developments that could increase risks from nuclear weapons.
The full post can be found here. It’s ~23,000 words, much of which is extensive quotes without added commentary from us. Some quotes are relevant to multiple sections and hence are repeated. But each section or subsection should make sense by itself, so readers should feel free to read only the sections that are of interest to them, to skim, and to skip repeated quotes and “Additional notes” sections. You can navigate to sections using the links in the summary table above.
This post is focused on what potential technological developments could increase risks from nuclear weapons. As such, this post is not necessarily claiming that these technologies will be net harmful overall, nor that nuclear risk will increase in future overall; both of those claims are plausibly true and plausibly false, and we don’t assess them here. Here are some further notes on what this post is vs isn’t focusing on and claiming:
Michael’s work on this post was supported by Rethink Priorities (though he ended up pivoting to other topics before having time to get this up to RP's usual standards). Will helped with the research and editing in a personal capacity. We’re grateful to Ben Snodin, Damon Binder, Fin Moorhouse, and Jeffrey Ladish for feedback on an earlier draft. Mistakes are our/Michael’s own.
If you are interested in RP’s work, please visit our research database and subscribe to our newsletter.
Just remembered that Artificial Intelligence and Nuclear Command, Control, & Communications: The Risks of Integration was written and published after I initially drafted this, so Will and I's post doesn't draw on or reference this, but it's of course relevant too.
This is a good post. Thank you for sharing. I disagree somewhat with your framework, because I think it is extremely important to differentiate factors that increase the likelihood of armed conflicts between nuclear powers and factors that increase the risk of nuclear escalation given a conventional conflict. I think that you've over-focused on the latter, and that drivers of the former are fairly important
For example, your analysis of UAVs and UUVs doesn't consider a risk I find highly salient: mutual misunderstanding of escalatory strength. That is, if the US shoots down an uncrewed Chinese intelligence balloon over US airspace, the escalatory action was China sending the balloon at all. If the US had shot down a crewed Chinese stealth fighter, reactions would have been very different. This holds even if the capabilities of the fighter and the balloon were identical.
Now, if the sole impact of UAVs is that there's a new step on the escalation ladder, that would probably be slightly beneficial. But if there's a step on the escalation ladder and Chinese and American political leadership disagree on where that step is, the potential for a situation to turn into a shooting conflict that takes lives increases substantially.
A similar point about escalation uncertainty can be raised by cybersecurity capabilities: militaries across the globe have made some steps towards defining how they think about cyberattacks. I believe that the most explicit statement on the topic comes from the French, but there are also advantages to strategic ambiguity, and genuine uncertainty about how publics in both authoritarian and democratic states would react to a cyberattack that, say, impaired the power grid.
Cybersecurity has the additional problem of, in the view of some experts, having incentives towards more provocative action, with a bias towards attackers under some circumstances.
As always, I do not speak for my employer or the US government.
An in-our-view interesting tangential point: It might decently often be the case that a technological development initially increases risks but then later increases risk by a smaller margin or even overall reduces risks.