This is one area where the benefits of modern technology have not been fully explored, not even by any peace movements. What most militants and media alike don’t get about the spectre of “smart weapons” is that the smartest and most economical defense requires the least offensive destruction. We now know definitively that countering terrorists’ destruction with even more destruction is just a recipe for creating ever more terrorists. What if we disabled their destructive capacity while preserving all nearby life instead? Where would their recruiting message go then?
Imagine instead of owning a gun or a knife to protect yourself, you own an inexpensive micro-bot swarm. Due to extremely efficient nanoscale materials allocation, each smart bot could become less than the price of a dumb bullet. When threatened, you could deploy your bot swarm to disable all immediate threats — such as by fouling the barrels and/or trigger mechanisms of any gun pointed in your general direction, softening or deflecting any objects swung your way, or defusing any incendiary devices in your proximity. Foams, mists, energy beams, decay catalysts, micro-welders, precise incisions, and even sedatives can be tactically deployed by these intelligent bot swarms to eliminate nearby weapon usability at minimal costs while preserving all lives involved.
Scale this concept of technological self defense up to a full community, then we can change the negative acronym WMD to stand positively for Weapons of Mass Disarmament. Then we can safely start repurposing all chemical and nuclear stockpiles for constructive energies instead of destructive threats.