Given the choice between an opponent with APM armaments and a standard infrastructure, or an opponent with standard armaments and an APM infrastructure, the latter is a greater military threat.
I’m not knowledgeable enough about modern military affairs to be certain of anything but I currently agree with this overall—though it depends on how advanced the APM tech is. The main advantages that APM provides generally fall into the categories of increasing the resources we can use and increasing the precision of our equipment. For the most part, I have difficult envisioning increasingly high quality/precise versions of any APM-based conventional weapon making a bigger war-time difference than APM’s potential ability to make large numbers of lower quality weapons while providing cheap vehicles for troops.
Some caveats exist to this though in unconventional weapons that do rely highly on precise design. In particular, the ability to make efficient, cheaply made autonomous drones and transport vehicles for them is a massive logistical advantage. Between reducing the risk of human life and allowing local recuperation of energy***, these sorts of weapons should quickly overwhelm weaponized civilian weapons without those advantages. That being said, if APM factories for certain civilian uses like power generation are included in APM infrastructure, I can envision a less tech-advanced opponent putting up a difficult enough fight to make war unwinnable. This is one of the points against military risk being low.
Still, APM infrastructure and APM weapons aren’t an either/or situation. More frequently, the strong nations will have both. This is one of the points in favor of military risk being low.
While APM-hybrid equipment may be inferior to APM-optimized equipment, it will probably still be superior to standard equipment.
I agree with this but suspect that the weaponry possibilities that APM opens up reach far beyond the purview of upgraded civilian tech to the extent that these improvements may not matter so much. This point also applies to the question of providing APM tech to belligerents—it depends on what the tech is.
The role of logistics (which is to say, infrastructure) in modern military affairs is widely underappreciated, and I have no reason to suspect Drexler of any particular expertise in this area.
Overall, I think the crux of the impact of APM lies in how accessible APM tech will be in the future. Because geographical constraints likely won’t be a limiting factor (see PeterMcCluskey’s response), this comes down to how good APM nations feel about giving APM to others. This means that the military risks of APM is likely one of the key factors in determining its effectiveness. In Drexler’s defense, it’s hard to predict the details of a massive change like APM and logistics often come down to small details that get very confused in high variance situations.
***Unlike nuclear weapons, abandoned or broken APM weapons have a relatively high risk of being salvaged for parts. Even if it provides a logistic advantage, I’m not sure that an APM nation would be willing to send very efficient motors/engines/energy harvesters into foreign territory for risk that the opponent takes those parts and hooks them into a weapon since those simple sorts of improvements can be a nightmare to combat. This argument also applies to providing other countries with APM energy sources and motor fabrication plants too.
I recently had a conversation with Christine Peterson and she pointed out the same thing. Imagine! A materials engineer who forgot that there was nitrogen in the air!
After some thinking, I also believe that nitrogen deficiency in Africa is not the concern that I indicated it was in the paper. I also agree that with sufficiently advanced technology (even when that technology is limited by physical laws), one should be able to overcome any geographical constraint in principle. This is Lesswrong and, thus, I must say that I was wrong about this.
Given that we can construct APM factories anywhere—something we likely can do once APM tech is achieved (though I suspect international interests would want to keep the APM tech used to create APM factories relatively inaccessible)--and that they can be maintained (again, something that APM can also ensure happens), I don’t imagine geography being an issue. Thus, I don’t really expect geography to be an issue.
I’m now much more confident that APM will lead to dramatic economic improvements in the places where we most care about them. There are still some practical considerations (i.e. ensuring the accessibility of people/machines capable of trouble-shooting the factories are everywhere the factories are) but these considerations are readily achievable.