I&#x27;d argue that sudden loss of antibiotic effectiveness is something that could roll us back into middle ages. Progress of technology is a powerful engine that seems self-sustaining at this point, but it&#x27;s mounted to the frame of society - and that frame is very fragile. That&#x27;s why I personally make such a big deal of this issue, or overreacting to terrorism threats. Because if the frame breaks and the engine halts, it may take many thousands of years to restart it. We&#x27;ve dug up all easily accessible high-density energy sources, so if we find ourselves back in pre-industrial era, it may take <i>a long time</i> to have another industrial revolution.