  In a non-sustainable, "over-populated" world, what might the use of
nanotechnology-based targeted, autonomous weapons mean for the future of
humanity? In order to gain some insights, we make a simplified game-theoretical
thought experiment. We consider a population where agents play the public goods
game, and where in parallel an epidemic unfolds. Agents that are infected
defectors are killed with a certain probability and replaced by susceptible
cooperators. We show that such "nanowars", even if aiming to promote good
behavior and planetary health, fail not only to promote cooperation, but they
also significantly increase the probability of repetitive epidemic waves. In
fact, newborn cooperators turn out to be easy targets for defectors in their
neighborhood. Therefore, counterintuitively, the discussed intervention may
even have the opposite effect as desired, promoting defection. We also find a
critical threshold for the death rate of infected defectors, beyond which
resurgent epidemic waves become a certainty. In conclusion, we urgently call
for international regulation of nanotechnology and autonomous weapons.
